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THE FUNGI WHICH CAUSE PLANT DISEASE 



THE MACMILLAN COMPANY 

NEW YORK • BOSTON • CHICAGO • DALLAS 
ATLANTA • SAN FRANCISCO 

MACMILLAN & CO., Limited 

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TORONTO 



THE FUNGI WHICH CAUSE 
PLANT DISEASE 



> 



BY 

F. L. STEVENS, Ph. D. 

PROFESSOR OF VEGETABLE PATHOLOGY AND DEAN, COLLEGE OP 

AGRICULTURE AND MECHANIC ARTS, MAYAGUEZ, PORTO 

RICO. FORMERLY OF THE NORTH CAROLINA 

COLLEGE OF AGRICULTURE ALSO FORMERLY 

PRESIDENT OF THE AMERICAN PHY- 

TOPATHOLOGICAL SOCIETY 



THE MACMILLAN COMPANY 

1913 

All rights reserved 






Copyright, 1913 

By the MACMILLAN COMPANY 

Set up and electrotyped. Published November, 1913 



<S)CI,A358112 



TO 

MY WIFE 

ADELINE CHAPMAN STEVENS 

IN ACKNOWLEDGMENT 

OF 

HELP, ENCOURAGEMENT 

AND INSPIRATION 



PREFACE 

This volume is intended to introduce to the student the more 
important cryptogamic parasites affecting economic plants in the 
United States, with sufficient keys and descriptions to enable 
their identification. Technical description of each division, order, 
family, genus and species when important is given unless the 
essential characters are to be clearly inferred from preceding keys 
or text. Gross descriptions of the host as diseased, i. e., of the 
disease itself, have been avoided since such are to be found in 
"Diseases of Economic Plants." Effort has been made to avoid 
duplication of matter contained in that volume. Abundant 
citations to the more important papers are given, sufficient, it is 
believed, to put the student in touch with the literature of the 
subject. 

While many parasites not yet known in the United States are 
briefly mentioned, especially the more important ones or those 
which are likely to invade America, no attempt has been made to 
list all of these. Non-parasitic groups closely related to those that 
are parasitic have been introduced in the keys merely to give a 
larger perspective to the student. 

Effort has been made to give at least one illustration of each 
genus that is of importance in the United States. 

The author is indebted for descriptions, keys, etc., to the 
various standard works. Those which have been drawn upon 
most largely are Saccardo's Sylloge Fungorum, Die Natiirlichen 
Pflanzenfamilien of Engler & Prantl, Clinton's Ustilaginales of 
North America, Clement's Genera of Fungi, and Minnesota 
Mushrooms, Plowright's British Uredinese and Ustilaginese, Ar- 
thur and Murrill each in North American Flora. 

The author wishes also to express thanks for suggestions and 
criticism of the manuscript to T. H. Macbride, who read the por- 
tion on Myxomycetes; J. J. Davis, Phycomycetes; L. R. Jones 

vii 



viii PREFACE 

and T. J. Burrill, Bacteria; G. M. Reed, Perisporiales; G. P. Clin- 
ton, Ustilaginales; J. L. Sheldon, Ascomycetes in part; D. Red- 
dick, Ascomycetes in part; J. C. Arthur, Uredinales; F. D. Heald, 
Fungi Imperfecti in part; F. C. Stewart, Fungi Imperfecti in part; 
H. Metcalf, Basidiomycetes in part; to Mrs. Flora W. Patter- 
son for aid in securing descriptions otherwise unobtainable; to 
Dr. Marshall Avery Howe for assistance with the glossary; to 
Messrs. Norton, Rosenkranz and Fawcett, for aid in proof- 
reading and in preparation of the manuscript, though no re- 
sponsibility for error attaches to those who have so kindly 
aided. 

It is probable, owing to the present unsatisfactory condition of 
taxonomy of the fungi, loose and imperfect description of species, 
disregard of generic limitation, lack of knowledge regarding the 
limits of specific variation, influence of environment, biologic host 
relations, etc., that many of the species treated in the text are 
untenable. The author has, however, attempted so far as possible 
to reflect the facts as they appear in the light of present knowledge 
and has deemed it more useful to err on the side of* conservatism 
than to attempt to reduce the apparent number of species by con- 
solidation without full and complete evidence as to the real identity 
of the species in question. 

F. L. Stevens. 
Mayaguez, Porto Rico. 



CONTENTS 

PAGE 

Introduction 1 

Division I, Myxomycetes 5 

Division II, Schizomycetes 13 

Bibliography of Introduction, Myxomycetes and 

Schizomycetes 53 

Division III, Eumycetes. . 59 

Class Phycomycetes 65 

Bibliography of Phycomycetes 109 

Class Ascomycetes 113 

Bibliography of Ascomycetes 288 

Class Basidiomycetes 298 

Bibliography of Basidiomycetes 466 

Fungi Imperfecti 475 

Bibliography of Fungi Imperfecti 666 

Bibliography of Books and Periodicals 678 

Glossary 681 

Index 697 



THE FUNGI WHICH CAUSE PLANT DISEASE 



INTRODUCTION 



The principal non-flowering vegetable parasites which cause 
plant diseases belong to three divisions: the Slime Molds (Myxo- 
mycetes) ; the Bacteria (Schizomycetes) ; and the True Fungi 
(Eumycetes including the Phycomycetes). The term fungi, in 
the broad sense, is often used to include all three of these divisions. 
All are devoid of chlorophyll and therefore all differ from the green 
plants in the essential ways which result from this deficiency. 
Transpiration, respiration, and true assimilation are the same as 
with the green plants, but photosynthesis or starch manufacture 
cannot be accomplished by them. Sunlight being thus useless to 
them directly they can live in the dayk as well as the light. Having 
no ability to elaborate their own foods from inorganic matter 
these organisms are limited to such nutriment as they can obtain 
from plants or animals which have elaborated it; that is, they must 
have organic foods for their sustenance. 

The fungi have acquired various food habits and adapted them- 
selves to different methods of nutrition. Some are nearly om- 
nivorous and can subsist upon almost any decaying tissue or upon 
soils or solutions rich with organic debris. Others thrive only 
upon special substances, as for example, some particular plant or 
animal, the host, perhaps only upon some particular part of that 
plant or animal. The organisms that prey upon living things are 
called parasites. Those living upon dead things are sapro- 
phytes. No hard and fast line can be drawn between these two 
classes. An organism which is usually a saprophyte may live 
upon a dead member of some plant, gradually encroach upon the 
still living part and thus become partially a parasite. Again there 
are times in the history of a plant when life ebbs so low that it is 
difficult to tell the living from the dead. The pulp of the apple 

1 



2 THE FUNGI WHICH CAUSE PLANT DISEASE 

when ripe, a resting seed, the cells of the potato tuber in winter, 
are undoubtedly alive, yet their activity is so little that many 
organisms can gain a foothold upon these stages of the plant 
that cannot do so at more vigorous periods of their exist- 
ence. 

Tubeuf ranks as hemi-parasites those organisms that usually 
are parasites, but may sometimes become saprophytic, and as 
hemi-saprophytes such as are usually parasitic, but may excep- 
tionally become saprophytic. These distinctions are of little 
import, other than to bring out clearly that each species has its 
own limits as to food requirements. 

It is hardly to be thought that these parasites and saprophytes 
have always been dependent organisms. The true fungi for ex- 
ample are best to be regarded as degraded descendants of algse, 
in which ancestors they once possessed chlorophyll and could 
prepare their own food from mineral matter by the aid of sun- 
light. 

No discussion of the general metabolic processes of the fungi is 
here necessary further than to indicate that among the products 
of their activity there are various excretions and secretions, which 
bear important relations to parasitism. Thus certain fungi grow- 
ing in artificial culture produce enzymes or organic ferments 
capable of softening and dissolving cellulose, also toxins, poisons 
which are capable of killing the cells of the host plant. Such 
enzymes and toxins are numerous and their bearing upon par- 
asitism is obvious. They enable the parasite to kill adjacent cells 
of the host and then to effect an entrance through the cell walls 
to the protoplasm and other nutrients contained within the 
cell. 

The presence of the parasite, or secretions produced by it, often 
calls forth abnormal growth responses from the host. These take 
very diverse forms, either the undergrowth or overgrowth, hyper- 
trophy, of single cells or tissues, or even the excessive development 
of large plant parts as in the case of the witches' brooms, and the 
"double flowering" of the dewberry. 

The probable relations of the groups under consideration to the 
other members of the Thallophyta are suggested in the following 
scheme. 






THE FUNGI WHICH CAUSE PLANT DISEASE 

'Bacteria, Schizomycetes. 
Cyanophyce/e, Blue-green Algse. 

Myxomycetes, Slime Fungi. 
Peridine^, Dinoflagellates. 

1 Conjugate, Conjugates. 
Diatome^. 
'Heterocont^. 

^"CHLOROPHYCEiE, Green Algse. 
^Charace^, Stoneworts. 
Rhodophyce^, Red Algae. 
^^"^^"EuMYCETES, Fungi. 



■Phycomycetes, Alga-like Fungi. 
■Ph^ophyce^, Brown Algaj. 



Key to the three Divisions important as plant parasites: 
Vegetative body a multinucleate naked plasmodium 

Division I. Myxomycetes, p. 5. 

Vegetative body a single-walled cell, nucleus absent or not of the 

form typical in the other fungi, reproduction by fission (by conidia 

in a few non-parasitic forms).. .Division II. Schizomycetes, p. 13. 

Not as above : Vegetative body usually filamentous, reproduction by 

various means Division III. Eumycetes, p. 59. 



DIVISION I 

MYXOMYCETES, SLIME MOLDS, SLIME 
FUNGI"-'* (p. 3) 

These are the lowest organisms considered by the botanist, and 
partake so much of the nature of both animals and plants that 
their position has long been debated. Their affinities are with the 
lowest living things, on the boundary between the animal and the 
vegetable kingdom, and sometimes more attention is accorded 
them by the zoologist than by the botanist. 

The distinctive character of this group is that the vegetative 
condition consists either of distinct amoeboid cells or of a mass of 
naked protoplasm, the Plasmodium, composed of numerous cell 
units, each unwalled. The plasmodia, at the completion of the 
free vegetative stage, produce numerous walled spores either free 
or in sporangia of various forms. The spores upon germination 
produce either zoospores or amoeboid bodies which multiply and 
unite to form either new plasmodia or pseudoplasmodia. 

The slime molds consist of three orders: 

Key to Orders of Myxomycetes 

Parasitic 1 . Plasmodiophorales, p. 5. 

Saprophytic 

Vegetative phase of free amoeba? 2. Acrasiales 

Vegetative phase plasmodia! 3. Myxogastrales, p. 9. 

The Acrasiales contain some five genera and ten species purely 
saprophytic. 

Plasmodiophorales 

Intracellular parasites; vegetative stage plasmodial; spores 
formed by the simultaneous breaking up of the Plasmodium into 
an indefinite number of independent cells. 

5 



6 THE FUNGI WHICH CAUSE PLANT DISEASE 

The Plasmodiophorales appear to include all of the true para- 
sites of the Myxomycetes. 

Key to Genera of Plasmodiophorales 

Spores free, spherical 1. Plasmodiophora, p. 6. 

Spores united into groups 

Spores in groups of four 2. Tetramyxa, p. 8. 

Spores in larger groups 

Spores forming a hollow sphere. ... 3. Sorosphaera, p. 8. 

Spores forming a spongy spore-ball 4. Spongospora, p. 8. 

Plasmodiophora Woronin 

This genus is parasitic in the living parenchyma of the roots 
of plants, the plasmodia filling the cells and causing galls at 
the point of attack. There are three species of the genus in 
Europe and America. 

P. brassicae Wor.^~*' ~^^~^^' ^os ^r^^g jong been known as a parasite 
on the crucifers generally and recent work indicates that other 
families, as the Umbelliferse and cucurbs, are also susceptible. -^^^ 

The parasitised cells especially, and the adjacent cells as well, 
are stimulated to enormous overgrowth; this hypertrophy result- 
ing in a characteristic root "clubbing." 

Study of diseased sections shows that the medullary rays and 
cortex are abnormally thick (hypertrophy and hyperplasia) and 
many of their cells are parasitized. Sclerenchyma cells are sup- 
pressed by the parasite and the xylem is reduced and phloem in- 
creased proportionately. The amount of stored starch is much 
less than in normal tissues. 

Infection does not appear to pass from cell to cell but groups of 
diseased cells are thought to arise from repeated division of a cell 
after its infection. 

In the enlarged host cells the protoplasm appears abnormally 
dense and fine grained. Eventually the whole lumen of the cell is 
occupied by the crowded, amoeboid, individuals, each uninucleate 
and unwalled, and still distinct from the other. These individuals 
later fuse into a Plasmodium the nuclei of which enlarge and un- 
dergo simultaneous mitotic division. Still later the mass divides 
into uninuclear segments each of which matures to a spore 1.6 ju 
in diameter, covered by a thin, smooth, colorless membrane. 



THE FUNGI WHICH CAUSE PLANT DISEASE 7 

The decay of the host liberates the spores in the soil. Their 
germination may be readily studied upon a microscope slide 
where in from five to twenty-four hours uninucleate zoospores 
are produced. The zoospores are differentiated into an inner 




10 11 

Fig. 1. — P. brassicse: 3, cabbage cells occupied by the unicellular parasite; 5, later 
stage, parasite many-nucleate; 10, host cell full of spores; 11, germinating 
spores. After Lotsy. 



granular part and an outer hyaline part, the hyaloplasm, which 
may extend to form pseudopodia, thus giving the cell an amoeboid 
movement in addition to that due to the single long cilium. In- 
fection by these swarm spores is supposed to occur through the 
root hairs though the mode of primary infection is not definitely 



8 THE FUNGI WHICH CAUSE PLANT DISEASE 

known. Seedlings raised in soil inoculated with chopped roots 
bearing the disease become badly diseased as do also seedlings 
upon which infected water is poured. 

P. humili Kirk is mentioned by Kirk ^ as the cause of club 
root of hops in New Zealand. 

P. vitis Viala & Sauvageau ; ^ P. calif ornica Viala & Sauvageau ; ® 
P. orchidis Massee ^° and P. tomato Abbey ^^ have been reported 
as the causes of serious diseases but their relation to the diseases 
and even their identity as actual organisms is seriously ques- 
tioned.12-14 

Tetramyxa Goebel grows upon water plants, notably Ruppia.^ 

Sorosphaera Schroter (p. 6) 

Parasitic in the parenchyma of living plants; spores elliptic- 
wedge shaped, forming a hollow, spherical spore ball. 

One species is found upon Veronica f a second species has been 
reported upon tea.^"^' 

S. graminis Schwartz is reported by Schwartz ^^"^ on the roots 
of Poa and other grasses where it caused nodules much resembling 
those of nematodes. 

Spongospora Brunchorst (p. 6) 

Similar to Sorosphaera but the spores forming a spore ball 
with open reticulations. 

S. subterranea (Wallr.) Lag.^^"^^ causes the powdery scab of 
potatoes in Great Britain, Europe and South America. It has 
been closely studied by Osborne ^^ who shows it to appear first in 
the tuber cells as a uninucleate myxamoeba which ultimately 
develops into a multinucleate amoeboid Plasmodium. 

Sorolpidium Nemec is a new genus with the species. 

S. betae Nemec which is on beets. ^^^ 

Several little known genera, kin to the above, attack algae, 
fungi, pollen, etc. 

Pseudomonas radicicola, the legume tubercle organism has been 
by some placed in this order under the name Phytomyxa legumi- 
nosarum. 



THE FUNGI WHICH CAUSE PLANT DISEASE 




Myxogastrales (p. 5) 

This order comprises some forty-seven genera and four hun- 
dred species of great variety and beauty. The Plasmodium, 
which varies from a millimeter or less 
to several decimeters in diameter, pro- ( \ ^\ 
duces either flat encrusted masses of \ ' ' ^C- \^ •'" 

spores, aethalia, or develops spores in \ '^ 

sporangia which show some superficial r 
resemblance to very small pufTballs, 
Fig. 2. The interior of the sporan- 
gium is often permeated by a thread- '^Tum-TSrercaTJ'arcoS'cr;^- 
like structure, the capillitium. They tais. After Macbride. 
are not parasites but occasionally injure plants by overgrowing 
them. 

Key to Families of Myxogastrales 

Spores not enclosed in a sporangium, borne 

externally upon the fruiting bodies. .. . 1. Ceratiomyxaceae. 
Spores enclosed in a sporangium 

Capillitium wanting, or very poorly de- »^ 
veloped 
Periderm of uniform thickness, rup- 
turing irregularly 2. Liceaceae. 

Periderm of unequal thickness 

Periderm with a subapical thin line, 

opening by an operculum 3. Orcadellaceae. 

Periderm unequally tliick above, the 
thin portions evanescent, leaving 
a network formed by the thicker 

portions 4. Cribrariaceae. 

Capillitium well developed 
Calcareous deposits absent, or rarely 
present in the periderm 
Capillitium of hollow, usually sculp- 
tured tlireads; spores light colored 5. Trichiaceae. 
CapiUitium of solid, smooth and 
usually much branched threads; 
spores dark colored 
Fruiting bodies sethalioid or in- 



10 THE FUNGI WHICH CAUSE PLANT DISEASE 

definite, walls poorly defined, 
fraying out into a pseudo- 

capillitium 6. Reticulariaceae. 

Sporangia definite, true capilli- 

tium more or less prominent 7. Brefeldiaceae. 
Fruiting bodies separate sporangia 
with columella and abundant 

capillitium 8. Stemonitaceae. 

Calcareous deposits present 
Capillitium not calcareous 

Capillitium simple 9. Didymiacese, p. 10. 

Capillitium more intricate 10. Spumariaceae, p. 11. 

Fructification calcareous throughout 11. Physaraceae, p. 11. 

Didymiaceae 

Fructification of separate sporangia or plasmodiocarps, periderm 
simple or double, the outer calcareous; columella present or ab- 
sent; capillitial threads thin, colorless or violet, arising from the 
base of the sporangium or passing from the columella to the peri- 
derm, usually without calcareous deposits, which if present are 
very small crystals; spores in mass black, spore walls violet. 

Key to Genera op Didymiaceae 

Calcareous deposits in the form of stellate crys- 
tals, frosting the surface 1. Didymium, p. 10. 

Calcareous deposits not stellate, 

Calcareous deposits forming a superficial crust 2. Diderma. 
Calcareous deposits forming large superficial 
scales 3. Lepidoderma. 

Didymium Schroter 

Sporangia distinct, stipitate, sessile or even plasmodiocarpous, 
never aethalioid; the peridium thin, irregular in dehiscence, cov- 
ered with a more or less dense coating of calcareous crystals; 
columella more frequently present ; capillitium of delicate threads, 
simple or sparingly branched, extending from the columella to the 
peridial wall. 

D. daedalium. B. & Br. is occasionally injurious to melons in 
culture. ^° 



THE FUNGI WHICH CAUSE PLANT DISEASE 11 

Spumariaceae (p. 10) 

Sporangia separate or aethalioid; calcarious deposit in the peri- 
derm or columella, never in the capillitium; capillitium radiating 
from various points of the columella, branching and anastomosing 
to form a network, the ultimate branchlets of which support the 
periderm. 

Key to Genera of Spumariaceae 

Fructification of ordinary sporangia 1. Diachea. 

Fructification sethalioid 2. Spumaria, p. 11. 

Spumaria Persoon 

Fructification ffithalioid, consisting generally of large cushion- 
shaped masses covered without by a white foam-like crust; within, 
composed of numerous tubular sporangia, developed from a com- 
mon hypothallus, irregularly branched, contorted and more or less 
confluent; the peridial wall thin, delicate, frosted with stellate 
lime crystals, which mark in section the boundaries of the several 
sporangia; capillitium of delicate threads, generally only slightly 
branched, terminating in the sporangial wall, marked with oc- 
casional swellings or thickenings. 

S. alba (Bui.) D. C. Like all other members of the order 
the present species is not a parasite but its aethalia are fre- 
quently produced upon grass, strawberries ^^ and other plants in 
such abundance as to cause more or less serious injury. The 
sporangia are fused into a large sethalium which is white or cream- 
colored, from 1 to 7 cm. long and half as thick. 

Physaraceae (p. 10) 

Key to Genera of Physaraceae 

Fructification aethalioid 1. Fuligo, p. 12. 

Fructification plasmodiocarpous or of distinct 
sporangia 
Peridium without lime 

Plasmodiocarpous 2. Cienkowskla. 

Sporangia distinct 3. Leocarpus. 

Peridium calcareous, more or less throughout 

Capillitium calcareous throughout 4. Badhamia. 



12 THE FUNGI WHICH CAUSE PLANT DISEASE 

Capillitium in part hyaline 

Sporangium vaselike, or more or less tubu- 
lar 

Opening irregularly 5. Physarella. 

Opening by a lid 6. Craterium. 

Sporangia various, dehiscence irregular 
Capillitium evenly branched ; the calca- 
reous nodes small, fusiform 7. Tilmadoche. 

Capillitium intricate 8. Physarum, p. 12. 

The species of Fuligo produce very large yellowish plasmodia 
which change to yellowish or brownish aethalia. Some are credited 
with damage similar to that of the preceding species. ^^ 

Physarum Persoon 

Sporangia plasmodiocarpous, sethalioid or distinct; the peridium 
usually simple, sometimes double, irregularly dehiscent, more or 
less definitely calcareous; capillitium a uni- 
form irregular net, dilated and calcareous at 
the nodes, adherent on all sides to the 
peridial wall. 

P. cinereum (Batsch), Pers., the species 
most commonly reported as injurious, forms 
its tiny sessile, gray sporangia in great num- 
bers on living plants, ^°' ^^^ often smother- 
„ „, ing them. The peridium is lime charged as 

Fig. 3.— Physarum ^ ^ . . . _<i 

sporangium. After are also the nodes of the . capillituim. The 

Macbride. i • i j. j a 

spores are brown or violet, and warty. 
P. bivalve F. has been noted as injuring young bean plants.^^ 
Dendrophagus globosus Toumey was reported by Toumey ^^ 
as the probable cause of crown gall, but such relation is doubt- 
ful (p. 36). It is said to be closely related to Physarum. 




DIVISION II 



BACTERIA, SCHIZOMYCETES 



(p. 3) 




a 

Fig. 4. — The three type forms of bacteria; 
a, spheres; h, rods; c, spirals. After Conn. 



Bacteria are extremely minute, unicellular organisms, which in 
outline present three primary forms each of great simplicity, 

namely the spheres (cocci), 

0( 



the straight rods (bacteria), 
the curved rods (spirilli). 

In addition to these forms 
which comprise the vast 
majority of known species 
of bacteria there are also 
bacteria consisting of fila- 
mentous bodies, either sim- 
ple or branched, attached or free. In both structure and phys- 
iology bacteria are allied to the vegetable kingdom and in it 
most closely to the blue green algae. 

Bacteria are inconceivably small. Most of the spherical bacteria 
fall within the limits of from 0.5 to 1.5 ju in diameter. Among 
the rod and curved bacteria the length in most species is between 
1 and 1.5 /t, the diameter between 0.5 and 1 /i. Among the 
largest species is B. megatherium, 2.5 x 10 ix] Clostridium butyri- 
cum, 3 X 10 m; and Spirillum volutans, 13 to 50 ^ long. Among 
the smallest is Spirillum parvum 0.1-0.3 n in diameter and Pseudo- 
monas indigofera 0.06 x 0.18 ix. 

It is practically impossible to conceive these dimensions. An 

illustration may aid the imagination. The paper on which these 

words are printed is about 87.5 m thick. It 

would therefore take about 200 bacteria of ordi- 

FiG. 5.— This dot is nary size or 400 moderately small or 20 very 

mm. m lameter. j^^^gg ^^^^ placed end to end to equal in length 

the thickness of this paper. It would take 1571 ordinary bacteria 
(1 X 2 /z) end to end to reach around the circumference of a dot 

13 



14 THE FUNGI WHICH CAUSE PLANT DISEASE 

1 mm. in diameter. (Fig. 5.) 500 to reach across it; and 392,700 
placed side by side or 785,400 if placed on end to cover its area, and 
about 500,000,000 to fill a cube the edge of which is 1 millimeter, 
making no allowance for lost space of the interstices. Considerably 
more than 500,000,000,000 bacteria of this size would find room 
enough to move about in a space of one cubic centimeter. 

The typical mode of increase among bacteria — the only mode 
except among the sheath bacteria — is by fission or direct divi- 
sion of one cell, the mother cell, into two, the daughter cells. 
Fig. 6. The rapidity with which fission can proceed depends of 
course upon conditions of environment, ranging from no growth 
at all, due to cold, lack of nutriment, presence of inhibiting sub- 
stance, to a maximum that varies with the species. For bacteria 



. J 1^ , . ,.,/Lm. ,/# ^v, M yJ Vw/^ 



Fig. 6. — Diagram illustrating the fission of bacteria, bacilli and cocci. 
After Novy. 

in general under very favorable surroundings, with proper tem- 
perature and abundance of food, from 20 to 40 minutes may be 
reckoned as a generation. In 24 hours, with the divisions once 
each hour, the progeny of one germ will be 16,777,216; with 
divisions each 30 minutes it will be (16,777,216)1 

If cell division be in one direction only and the resulting daugh- 
ter cells remain undisturbed, a thread-like row results. If cell 
division be in two planes, and the resulting cells adhere in groups, 
tablets of 8, 16, and 64 will occur frequently. If the division be 
in three planes and their cells adhere, packets result. 

The structure of the bacterium cell owing to its minuteness 
is yet very incompletely known. The most enduring portion of 
the vegetative cell is the cell wall. This is surrounded by a layer, 
the capsule and bears the flagella. The number of the flagella 
and their position varies in different species. Some species have 
none, some one, two, or many. They may be at the ends, polar, 



THE FUNGI WHICH CAUSE PLANT DISEASE 



15 




^Mmnr^^mmm 




Fio. 7. — Spores of bacteria showing their position 
within the cells. After Frost & McCampbell. 



or scattered over the whole surface, diffuse or peritrichiate. 
They are the organs of locomotion. Within the wall is the pro- 
toplast consisting of a peripheral layer, inner strands, imbedded 
granules and vacuoles bearing cell sap. The existence of a nucleus 
comparable to that in higher plants is a much controverted point. 
Spores: Typically a bacterial spore consists of a highly refractive, 
ovoid, walled body within the mother cell. This body possesses 
high resistance to ordinary stains, a great tenacity against de- 
colorizing if it be once 
stained, a higher resist- 
ance against adverse tem- 
peratures and adverse 
conditions generally than 
do vegetative cells, and 
finally the ability to ger- 
minate and thus aid in 
perpetuating the species. 
While the absolute num- 
ber of bacterial species 
that form spores is large, comparatively they are few. They are 
most frequently met among the rod forms, and are rare among 
the spirilla and cocci. None are known among the important 
plant pathogens. 

In the simplest cases of spore formation, the protoplasm be- 
comes more dense in some part of the mother cell, the remaining 
protoplasm of the cell is drawn around the denser mass, and the 

whole resulting dense region becomes 
enclosed within a special wall. Usually 
in this process nearly all the protoplasm 
of the mother cell, the sporangium, is 
used. The mother cells during spore 
formation may remain of the normal 
Fig. 8.— Spore formation in vegetative size and shape; they may 

bacteria. After Fischer. ^^^^ ^^ (g subtilis) Or abandon (B. 

megatherium) the habit of thread formation. Bacteria of many 
species become swollen at the point where the spore develops, 
Figs. 7 and 9; be this in one end (Vibrio rugula) or in the middle 
(B. inflatus). The swelling at the end is very common, giving rise 




16 



THE FUNGI WHICH CAUSE PLANT DISEASE 



to the peculiar and characteristic form known as "Nail Head" or 
"Drum Stick" bacteria. In nearly all species of the Eubacteria 
the spores are solitary. 

There are three modes of spore germination. The most com- 
mon, polar germination, consists in a rupture of one pole of the 
spore and the development of a normal vegetative cell through 
the opening. The second mode, equatorial, Fig. 9, consists in a 
rupture in the side instead of the end of the spore. The third mode, 





Fig. 9. — Spores of bacteria, showing bispored cells, spore formation and spore 
germination. After Prazmowski, De Bary and Koch. 

absorption, consists in a direct development of the whole spore 
into a vegetative cell. In suitable environment germination may 
occur immediately after spore formation; if conditions be unsuit- 
able it may be delayed for many years. 

Under certain conditions most bacteria undergo abnormal 
changes in form becoming elongated, branched, swollen, bulged, 
curved, or variously, usually irregularly, distorted. Such are 
termed involution forms. They are in most cases due to unfavor- 
able conditions of temperature and nutriment, and the bacteria 
resume their normal form when again in normal environment. 

The branched forms found in root tubercles after the period of 
luxuriant growth has passed, and the branched thread-like growth 
of the bacterium of human tuberculosis upon artificial media, are 
by many regarded as involution forms. 



THE FUNGI WHICH CAUSE PLANT DISEASE 17 

Constancy of Species. Bacteria in nature and under artificial 
conditions remain true to species. There may be variation from 
generation to generation as among all other plants or animals of 
the world, and by the slow process of evolution, a species may in 
many generations become modified, leading eventually to new 
races, varieties, and possibly species. That one species can change 
directly and suddenly to another, much less a species of one genus 
into a species of another genus, is not to be credited. Marked 
variation is brought about in many species by change in tempera- 
ture, food, oxygen supply, etc., changes in size, form, sporulation, 
flagellation, virulence, chromogenesis, fermentative power, group- 
ing, etc. These changes belong to the life cycle of the species and 
occur as reactions to the environment. 

Bacteria were discovered by Loewenhoek in 1683. That they 
do not originate spontaneously was shown by Pasteur in 1860-4. 
The first disease producing bacteria were recognized in anthrax by 
PoUander & Davaine in 1849; and the first definite proof that 
bacteria actually cause animal disease was made by Koch with 
anthrax in 1875-1878. The first plant disease to be definitely as- 
cribed to bacteria was the pear blight by Burrill in 1879. The 
invention of the cotton plug, Schroeder & Dusch, 1853, the gela- 
tine method of plating for the isolation of species, Koch, 1881, 
and the use of stains, Weigert, 1875, were practically necessary 
prerequisites to any considerable advance in bacteriology. For 
long it was contended, especially by European bacteriologists, 
that bacteria do not cause plant diseases but most convincing 
proof to the contrary was adduced by E. F. Smith. 

Entrance to the host plant is made in various ways, very often 
through wounds, particularly wounds caused by insects,, through 
roots, stomata, water pores, through delicate tissues as blossoms, 
etc. Once in the tissue, bacteria may migrate rapidly by means 
of the vessels, intercellular spaces or more slowly through cavities 
dissolved by the aid of enzymes. 

Classification. In all there are some thirty-six well recognized 
genera embracing twelve hundred or thirteen hundred purported 
species of bacteria. This number will doubtless be greatly de- 
creased when the organisms have been well studied, by finding 
that many so-called species are not really distinct. The number 



18 THE FUNGI WHICH CAUSE PLANT DISEASE 

will also of course receive many additions of forms not as yet 
known. 

No system of classification can yet be said to have general 
acceptance and all classifications now in vogue will undoubtedly 
undergo minor changes and perhaps changes in fundamental 
conception. 

The system of Migula^^ meets probably with most favor. 
With the omission of genera of little import pathologically, and 
with the introduction of the order Myxobacteriales, it is as follows : 

SCHIZOMYCETES (p. 3) 

Fission plants, without phycochrome, dividing in one, two or 
three directions of space. Reproduction by vegetative multiplica- 
tion. Resting stages, endospores, exist in many species. Motility 
by means of flagella in many genera. 

Key to Orders, Families, and Genera of Schizomycetes 

Cells without sulphur or bacterio-purpu- 

rein Order I. Eubacteriales. 

Cells in free condition gobular; in di- 
vision somewhat elliptical I. Coccaceae, p. 21. 

Nonflagellate 

Division in only one direction, 

cells single, in pairs, or chains 1. Streptococcus. 
Division in two directions; cells 

may remain in plates 2. Micrococcus, p. 21. 

Division in three directions cells 
may remain in bale-like 

packets 3. Sarcina. 

Flagellate 

Division in two directions 4. Planococcus. 

Division in three directions. . 5. Planosarcina. 
Cells long or short, cylindrical, 
straight, division in one direc- 
tion II. Bacteriaceae, p. 21. 

Nonflagellate 6. Bacterium, p. 21. 

Flagellate 

Flagella diffuse 7. Bacillus, p. 37. 

Flagella polar 8. Pseudomonas, p. 22. 



THE FUNGI WHICH CAUSE PLANT DISEASE 19 

Cells spirally curved or represent- 
ing part of a spiral, division in 

one direction III. Spirillaceae. 

Cells cylindric in sheathed threads. . . IV. Chlamydobacteriaceae. 

Cells with sulphur Order II, Thiobacteriales. 

Motile rods in pseudoplasmodial masses 
in a gelatinous matrix, and forming 
highly developed cysts Order III. M3rxobacteriales. 

The species of families 3 and 4 and of orders II and III, some 
twenty-five genera in all, are so far as is known, unimportant as 
regards plant disease. All of the known plant pathogens belong 
to one or other of the first two families of the Eubaeteriales. Each 
of these families contains several dangerous parasites upon ani- 
mals, e. g., Bacillus typhosus, Spirillum cholerae-asiaticse, Bacte- 
rium tuberculosis. 

The specific characters of bacteria are chiefly chemical or 
physiological and rest in the relation of the forms to oxygen, gel- 
atine liquefaction, fermentation of various sugars, acid production, 
relation to nitrogenous compounds, chromogenesis, etc.^^' ^'' "°^ 

To enable brief expression of these characters the Society of 
American Bacteriologists endorses the following numerical sys- 
tem.* 

A Numerical System of Recording the Salient Characters of an 
Organism. (Group Number) 

100. Endospores produced 

200. Endospores not produced 

10. Aerobic (Strict) 

20. Facultative anaerobic 

30. Anaerobic (Strict) 

1. Gelatine liquefied 

2. Gelatine not liquefied 

0.1 Acid and gas from dextrose 

0.2 Acid without gas from dex'trose 

0.3 No acid from dextrose 

0.4 No growth with dextrose 

* This will be found useful as a quick method of showing close relationships 
inside the genus, but is not a sufficient characterization of any organism. 



20 



THE FUNGI WHICH CAUSE PLANT DISEASE 



.01 


Acid and gas from lactose 




.02 


Acid without gas from lactose 




.03 


No acid from lactose 




.04 


No growth with lactose 




.001 


Acid and gas from saccharose 




.002 


Acid without gas from saccharose 




.003 


No acid from saccharose 




.004 


No growth with saccharose 




.0001 


Nitrates reduced with evolution o 


■gas 


.0002 


Nitrates not reduced 




.0003 


Nitrates reduced without gas formation 


.00001 


Fluorescent 




.00002 


Violet chromogens 




.00003 


Blue 




.00004 


Green " 




.00005 


Yellow " 




.00006 


Orange " 




.00007 


Red 




.00008 


Brown " 




.00009 


Pink 




.00000 


Non-chromogenic 




.000001 


Diastasic action on potato starch, 


strong 


.000002 


Diastasic action on potato starch, 


feeble 


.000003 


Diastasic action on potato starch, 


absent 


.0000001 


Acid and gas from glycerine 




.0000002 


Acid without gas from glycerine 




.0000003 


No acid from glycerine 




.0000004 


No growth with glycerine 





The genus according to the system of Migula is given its proper ab- 
breviation which precedes the number thus : * 

Bacillus coli (Esch.) Mig. becomes B. 222.111102 

Bacillus ALCALiGENES Petr. " B. 212.333102 

PsEUDOMONAS CAMPESTRis (Pam.) E. F. Sm. " Ps. 211.333151 

Bacterium suiciDA Mig. " Bact. 222.232203 



* Incomplete group numbers are given with many of the species in suc- 
ceeding pages. In these the known factors are given and the unknown or 
imperfectly known are represented by dashes. These numbers were worked 
out for the author by Mr. W. C. Norton, from the available literature. 



THE FUNGI WHICH CAUSE PLANT DISEASE 21 

The plant pathogens as yet known, with few exceptions, belong 
to the two genera Pseudomonas and Bacillus between which they 
are about equally divided. 

In the earlier days of bacteriology and to some extent in recent 
days, bacteria have been seen in diseased plant tissues and have 
been placed by their observers in one genus or another and cited 
as the causes of the diseases in question but without actual evi- 
dence that they cause the diseases and very often without any real 
evidence as to the genus to which the bacteria belonged. It is 
of course usually impossible to identify such forms and they must 
be dropped from consideration. 

Coccaceae (p. 18) 

No representative of this family parasitic upon plants has yet 
been reliably recorded in America. Micrococcus tritici Pril -'' 
upon wheat in England is probably in reality Bacillus prodigiosus 
and not pathogenic. Micrococcus phytophthorus Frank ^^ -^ re- 
ported as a cause of potato rot and also associated with potato 
black-leg is perhaps in reality identical with Bacillus phytoph- 
thorus Appel. Micrococcus nuclei Roze, M. imperiatoris Roze, 
M. flavidus Roze, M. albidus Roze, M. delacourianus Roze and 
M. pellucidus Roze are assigned by Roze -' as the causes of va- 
rious potato troubles in Europe, and M. populi Del.^^ is said to be 
the cause of canker on Populus. 

Bacteriaceae (p. 18) 

Bacterium Ehrenberg (p. 18) 

These non-motile forms, perhaps owing to their lack of power 
of locomotion, are comparatively rare as plant pathogens. 

Bact. briosianum Pav. is given as the cause of rotting of to- 
mato fruit and distortion of vegetative parts in Italy. ^^° It is 
described also on Vanilla. '"^° 

Bact. montemartinii Pav. is described as the cause of a canker 
of Wisteria. ^^- 

Bact. mori B. & L. is said to cause leaf and branch spots on 
mulberry. ^^^ 



22 THE FUx\GI WHICH CAUSE PLANT DISEASE 

Bact. teutlium Metcalf.-^ (Group number 222.— 220— .) 

A short rod with rounded ends, 1.5 x 0.8 ix, before division 
3 X 1 ju; non-motile, no flagella seen; no spores; Gram-positive; 
agar colonies round, thin, riot viscid, porcelaneous to transparent, 
seldom over 0.5 ix. No liquefaction. Broth clouded, precipitate 
thin or none, no pelhcle. Milk not coagulated. T. D. P. 45°. 
10 min. Opt. 17°. Aerobic, no gas. 

Beets diseased by this organism were honeycombed with pockets 
filled with a viscous fluid, a practically pure bacterial culture. 
The vascular tissue was not rotted. Inoculation by pricking the 
bacterial exudate into healthy beets resulted in typical disease. 
Pure cultures isolated by use of cane-sugar-agar gave similar results. 
Three weeks after inoculation the exudate-forming pockets were 
typically developed. Surface inoculation failed and there is no 
evidence that the organism can infect except through wounds. 
No rotting followed inoculation on potato, white turnip, radish, 
tomato, or apple. 

Bact. pini Vuill.^° was found in tissue of pine galls and regarded 
as their cause. 

Bact. fici Cav.^^^ is reported as the cause of a disease of figs. 

Bact. scabigenum Busse & v. Faber is described as the cause 
of scab of sugar-beets in Germany.^^ 

Pseudomonas Migula (p. 18) 

Short or long rods motile by polar flagella, fig. 10, whose num- 
ber varies from one to ten but is most commonly one. Endo- 
spores are sometimes present. The cells in some species adhere 
to form short chains. The basis of separation into species is the 
growth upon gelatine, character of the colonies, chromogenesis 
and numerous other cultural characters.^'-* ^^' ^^ 

Something over seventy-nine species are known, at least fifteen 
of which cause diseases in plants, some of them very serious. 
Many other species occur in water, soil and manure, while others 
are suspected animal pathogens. 

One prominent group of plant pathogens, ^^ the yellow Pseudo- 
monas group, contains, according to Smith, Ps. campestris, Ps. 
phaseoli, Ps. hyacinthi, Ps. stewarti, Ps. juglandis, Ps. vascularum, 
Ps. dianthi, Ps. amaranti, Ps. malvacearum. These, he says, 



THE FUNGI WHICH CAUSE PLANT DISEASE 23 

agree in the following particulars: They are yellow rod-shaped 
organisms of medium size, straight or slightly crooked with 
rounded ends. The segments multiply by fission, after elongation. 
They are generally less than 1 /x in diameter. The segments 
occur singly, in pairs or in fours joined end to end, or in clumpy 
masses of variable size (zoogloece), more rarely they are united 
into long chains or into filaments in which no septa are visible. 
Endospores have not been observed. The segments are motile by 
means of one polar flagellum which is generally several times as 
long as the rod, and may be wavy or straight when stained. The 
species grow readily on all of the ordinary culture media, but so 
far as is definitely known all are strictly aerobic. None are gas 
producers. They do not reduce nitrates to nitrites. The yellow 
color appears to be a lipochrome and in the different species varies 
from deep orange and buff-yellow, through pure chrome and 
canary-yellow, to primrose-yellow and paler tints. 

Ps. aeruginosus Del. possibly identical with Ps. flourescens- 
putridus Flugge is the cause of a leaf and stem disease of tobacco 
in France.^' 

Ps. avenae Manns, (Group number 111.2223032.) A short rod 
with round ends, 0.5 to 1 At x 1 to 2 m- Actively motile, generally 
by one polar flagellum, occasionally by two or three. Gram 
negative. What seem to be endo- 
spores are found in old cultures. On 
agar stroke, growth very slow, fili- 
form, rather flat, glistening; margin 
smooth, opaque to opalescent; non- 
chromogenic. Liquefaction occurs on 
gelatine in seven to twelve days. 
, Broth is slowly clouded. Agar colo- 
nies, amorphous, round with surface 
smooth, edges entire. No gas in 
dextrose, saccharose, lactose, maltose, Fig. lo.— Ps. avenae. After 

, . . . I'll Manns. 

or glycerme. Ammonia and mdol 

not formed. Nitrates reduced to nitrites. T. D. P. 10 min., 

60°, Opt. 20° to 30°. 

This organism was isolated and described by Manns in 1909,^^ 
as the cause of a serious oat blight. Inoculations with it alone by 




24 THE FUNGI WHICH CAUSE PLANT DISEASE 

hypodermic injection produced only limited lesions but similar 
inoculations with a mixed culture of Ps. avense and Bacillus avense 
produced typical disease. Manns, moreover, noticed that the 
virulence of the Pseudomonas decreased when kept in culture free 
from the Bacillus, also that in the disease as it occurs in nature 
these two organisms are associated. His conclusion is that the 
Pseudomonas is the active parasite and that the Bacillus is an 
important, perhaps a necessary symbiont. 




2 

Fig. 11. — Showing effect of inoculation of Ps. campestris into cabbage plants. Nos. 
1 and 2, six weeks after inoculation. No. 3, check plant uninoculated. After 
Russell. 

Infection in nature is chiefly stomatal by spattering rain. 
Soaking of seed in suspensions of bacteria did not produce the 
disease. Inoculations on wheat failed, though from one variety 
of blighted wheat. Extra Square Head, the typical organism was 
isolated. Inoculations on corn made during wet weather produced 
lesions which spread rapidly and the organism was re-isolated. 
Barley is said by Manns to be susceptible and what he believes to 
be the same disease occurs on blue grass and timothy. 

Ps. campestris (Pam.) E. F. Sm. (Group number 211.333151.) 
A rod-shaped, motile, organism generally 0.7 to 3.0 x 0.4 to 0.5 f^; 
color dull waxy-yellow to canary-yellow, occasionally brighter or 
more pale. One polar flagellum; no spores known. Aerobic but 



THE FUNGI WHICH CAUSE PLANT DISEASE 



25 



not a gas or acid producer, gelatine liquefied. Cavities are formed 
around the bundles but the organism seems to be only feebly 
destructive to cellulose. A brown pigment is produced in the 
host plants and on steamed cruciferous substrata. Growth 
rapid on steamed potato cylinders at room temperatures, without 
odor or brown pigment. Growth feeble at 7°, rapid at 17 to 19°, 
luxuriant at 21 to 26°, very feeble at 37 to 38° and ceases at 40°. 
T. D. P., 10 min., 51°. 




Fig. 12. — Ps. campestris. Section of a cabbage leaf par- 
allel to the surface and near the margin, showing the 
result of infection through the water-pores. After 
Smith. 

It is closely related to Ps. hyacinthi from which it differs chiefly 
in its pathogenic properties, its duller yellow color and its higher 
thermal death point. It is troublesome upon cabbage, turnips, 
cauliflowers, coUards; and a very large number of cruciferous 
hosts, both cultivated and wild are susceptible. It enters the host 
plant through the vascular system which becomes decidedly 
brown. 

This organism was first isolated by Pammel ^^ (see also ^^) from 
rutabagas and yellow turnips in 1892; green-house inoculations 
with pure cultures were made in scalpel wounds, which were then 



26 



THE FUNGI WHICH CAUSE PLANT DISEASE 



sealed with wax. The plants showed rot in a few days and the 
actual causal relation of the organism was thus established. Con- 
firmatory evidence was gained by Russell ^^ from puncture inocula- 
tions in cabbage and 
cauliflower petioles. It 
was further shown by 
E. F. Smith ^^ that the 
cabbage and turnip or- 
ganisms are identical 
and that the bacteria, 
by solution of the cellu- 
lose, produce pits and 
holes through the walls 
of the host cells re- 
sulting eventually in 
large cavities. 

Infection was shown 
by Russell ^^ and by 
Smith 3«' 39 to be chiefly 
through the water pores 
or through wounds 
made by insects; the 
bacteria being air or 
insect borne and de- 
rived largely from in- 
fected soil. After en- 
tering the plant the 
bacteria multiply rap- 
idly, and migrate in 
every direction by 
means of the veins. 
Studies of Harding, Stewart and Prucha ^° (see also) ^^ showed 
that it can survive the winter on the seed and thus infect seedlings. 
Ps. destructans Potter ^^ is described as an uniflagellate organism 
causing a destructive soft rot of turnips and beets in England. 
Doubt has been thrown upon its identity by the work of Harding 
and Morse ^^ and of Jones ^^ who found supposedly authentic 
cultures to bear peretrichiate rather than polar flagella. See p. 42. 




Fig. 13. — Ps. campestris; cross-section of a turnip 
root. After Smith. 



THE FUNGI WHICH CAUSE PLANT DISEASE 27 

Ps. dianthi Arth. & Boll.^^ Though originally reported as the 
probable cause of carnation leaf spot, this organism is now regarded 
as a saprophyte. 

Ps. fluorescens (Flugge) Mig. Straight and curved rods of 
medium size in chains of two or several members. Cells 0.68 x 
1.17-1.86 ji. Spores not seen. Flagella 3-6 polar. 

Gelatine liquefied; surrounding medium colored greenish-yellow; 
Gram negative. Milk not coagulated. Indol weak. Bouillon, 
turbid, fluorescent. 

This organism or two varieties of it are by Barlow ^^ held re- 
sponsible for a decay of celery. The organism was found in large 
numbers in the decayed tissue; was isolated and typical rot was 
induced by inoculation of pure cultures upon sterilized celery 
stems. 

It is also credited with two distinct types of tobacco disease in 
France, one of them on seed, the other on the growing plant. 
Recently Griffon ^^ has claimed that both of the varieties, Ps. 
fljorescens liquefaciens and Ps. putrida are capable of producing 
wet rot of various vegetables, carrots, rutabagas, tobacco, toma- 
toes, melons, and that the latter organism is identical with Ps. 
seruginosus. It is also held that B. brassicaevorus and B. cauli- 
vorus are forms of Ps. fluorescens. 

Ps. fluorescens exitiosus v. Hall is said by van Hall ^° to cause 
rot of Iris. 

Ps. hyacinthi (Wak.) E. F. Sm., is a serious pest of hyacinths in 
the Netherlands but has not yet been recorded in America.^® 
It is medium sized rod with rounded ends, 
measuring in the host 0.8-1.2 x 0.4-0.6 n; 
actively motile by one long polar flagellum; 
non sporiferous; liquefies gelatine slo\yly; 
aerobic; no gas. It produces indol. Does not Fig. i4.—Ps. hyacinthi. 
grow at 37°. Opt. 28 to 30°, T. D. P. 10 '^^*'' ®°'^*^- 

min., 47.5°. It is a wound parasite which grows in the vessels 
forming a bright yellow slime and is closely related to Ps. cam- 
pestris and Ps. phaseoli. 

Ps. iridis v. Hall ^° is described by van Hall as the cause of 
decay of shoots and rhizomes of Iris. 

Ps. juglandis Pierce. (Group number -11. 51-.) ^^ A rod 




28 THE FUNGI WHICH CAUSE PLANT DISEASE 

1-2 X 0.5 11, with rounded ends, actively motile by one long polar 
flagellum. Bright chrome-yellow in growth; disastatic ferment 
present. No gas; aerobic. It was isolated from diseased nuts, 
leaves, and twigs of English walnut in California in 1901. In- 
oculations by spraying demonstrated its pathogenicity. The 
organism is closely related to Ps. campestris but is distinguished 
from it by the abundant bright yellow pigment produced upon the 
surface of extracts of leaves of walnut, magnolia, fig, castor bean 
and loquat. 

Ps. leguminiperdus (v. Oven.) Stev.,^^ said to be distinct 
from Ps. phaseoli, occurs on peas and other legumes. It was 
isolated, cultivated and inoculations made. 

Ps. levistici Osterw.^^ occurs on Levisticum. 

Ps. maculicolum (McC.) Stev. (Group number 211.3332023.) 
A short rod, forming long chains in some media. Ends rounded. 
Size from leaf 1.5 to 2.4 /x by 0.8 to 0.9 /x; in 24-hour beef-agar 
culture, 1.5 to 3 ix by 0.9 m- No spores, actively motile, one to 
five polar flagella two to three times the length of the rod. Mo- 
tile in most artificial media. Involution forms in alkaline beef 
bouillon. Pseudo-zoogloeae in Uschinsky's solution. Gram nega- 
tive. Stains readily with carbol fuchsin and with an alcoholic 
solution of gentian violet. 

Agar plate colonies visible on the second day as tiny white 
specks, in three to four days, 1 to 3 mm. in diameter, white, 
round, smooth, flat, shining, and translucent, edges entire, with 
age dull to dirty white, slightly irregular, edges undulate, slightly 
crinkled, and with indistinct radiating marginal lines. Buried 
colonies small, lens-shaped. 

Agar streak cultures white, margins slightly undulate. Beef 
bouillon clouds in twenty-four hours. Growth best at surface 
where a white layer, not a true pellicle, is formed. No zoogloese. 
No rim. 

Gelatine stab cultures liquefied in eight to ten days. Growth 
from surface crateriform; slight, white, granular precipitate. Slight 
green fluorescence. No separation into curd and whey. Indol 
production feeble. T. D. P. 46°. Opt. 24-25°. Max. 29°. Min. 
below 0°. 

Isolated from cauliflower leaves on which it forms brownish to 



THE FUNGI WHICH CAUSE PLANT DISEASE 



29 



purplish-gray spots 1-3 mm. in diameter. ^°^ Pathogenicity on 
this host also on cabbage was proved by inoculation. Its entrance 
is stomatal. 

Ps. malvacearum, E. F. Sm.^"*' ^'' ^°^ This yellow organism, 
pathogenic on cotton, much resembles Ps. campestris but its slime 
is more translucent on potato and it 
does not attack the cabbage. It was 
grown in pure culture by Smith and 
successful inoculations were made by 
spraying a suspension of a young agar 
culture of the organism upon cotton 
leaves and bolls. No description has 
been published. 

Ps. medicaginis Sackett.^^ (Group 
number 212.3332133.) A short rod, 
1.2-2.4 X 0.5-0.8 m; filaments 20.2- 
37.2 n long. No spores; actively 
motile with 1^ bipolar flagella; cap- 
sules and zooglcea none. Agar streak 
filiform, later echinulate, glistening, 
smooth, translucent, grayish-white; 
no gelatine liquefaction; bouillon 
slightly turbid, pellicle on third day, 
sediment scant. Milk unchanged. 
Agar colonies round, grayish-white. 
No gas or indol. Optimum reaction 
+ 15 to +18 Fuller's scale. T. D. P. 
49-50°, 10 min. Opt. 28-30°. Aerobic, 
zymase, rennit or pepsin. 

It occurs as a pathogen on alfalfa and issues in clouds visible to 
the naked eye from small pieces of tissue of the diseased stem or 
leaf when mounted in water on the shde. These clouds under the 
high power resolve into actively motile rods, relatively short and 
thick. The bacteria are also found in practically pure culture in 
the exudate which oozes from the diseased tissue as a clear viscous 
liquid and collects in drops or spreads over the stem. Sackett 
with pure culture inoculations produced the typical disease and 
re-isolated the organism with unchanged characters. Re-inoculated 




Fig. 15. — Ps. malvacearum. 
Early stage of stomatal infec- 
tion in angular leaf-spot of 
cotton. After Smith. 

No diastase, invertase, 



30 THE FUx\GI WHICH CAUSE PLANT DISEASE 

it again caused disease. More than a hundred inoculations by 
scarification or puncture gave one hundred per cent infection. 
Controls remained undiseased. Infection, stomatal or water pore, 
was also secured through the apparently unbroken epidermis. 

The virulence of the or- 
ganism was retained after 
five months on agar. It 
is beheved that the usual 
mode of infection is 
through rifts in the epider- 
mis due to frost and that 
the germ is wind-borne 
from infected soil. 

Ps. michiganense (E. 
F. Sm.) Stev. (Group 

number -22. 252-.) 

Rod short with rounded 
ends, 0.35-0.4 x 0.8-1.0 /x. 

Fig. 16.— Ps. medicagiiiis; 4S-hour agar-oulture, No motility seen from 
showing formation of filaments. After Sackett. ^^^^^^ Flagella apparently 

polar but not seen distinctly. Agar colonies pale-yellow, smooth, 
round. Agar stab canary-yellow, opaque, viscid. Bouillon moder- 
ately clouded, a moderate sUmy precipitate; no rim or pellicle. 
Gelatine not liquefied. 

The organism was described by Smith ^^ as the cause of a stem 
disease of tomatoes in Michigan. No fungi were seen but bacteria 
were present in great numbers in the bundles also in cavities in 
the pith and bark. The organism was isolated and the disease was 
produced both by pure culture inoculations and by crude inocula- 
tions, using an impure inoculum. The disease caused is less rapid 
in development than that caused by B. solanacearum and less 
browning of the infected tissue occurs. 

Ps. mori (B. & L.) Stev. (Group number 222. 202-.) Rod 

with rounded ends, 1.8-4.5 x 0.9-1.3 /x, mostly 3.6 x 1.-2 /x; 
motile by one, sometimes two polar flagella. No spores. Pseudo- 
zoogloese present. Agar colonies round, smooth, fiat. Agar 
streaks spreading, flat, dull-white. Gelatine stab filiform, no 
liquefaction. Milk not coagulated. No gas. T. D. P. 51.5°. 




THE FUNGI WHICH CAUSE PLANT DISEASE 31 

In 1894 Boyer and Lambert '°^ produced successful inoculations 
on mulberries with an organism to which they gave the above 
name, but without description. 

In 1908 E. F. Smith. ^^ plated out, from blighted mulberry 
leaves collected 
in Georgia, a 
white species 
with which he 
made numerous 
infections on 
both stems and 
leaves of mul- 
berry. From 
these cultures 
Smith supplied 
the description 
quoted in part 
above. The re- 
1 a t i o n which 
Bacillus cuboni- 
anus '"^ has to 
this mulberry 

rlicoQCP ic nn ^^G. 17. — Ps. medicaginis; agar colonies 7 days old, deep 
uibedbe lb uii- ^^^ surface colonies by reflected light. After Sackett. 

known. 

Ps. phaseoli E. F. Sm. A short round-ended rod, wax-yellow 

to chrome; motile; anaerobic. Milk coagulates, and the whey 

slowly separates without acidity; gelatine liquefies slowly. Growth 
feeble at 37°, none at 40°. T. D. P. 10 min., 
49.5°. A starch enzyme is produced and the 
middle lamella also dissolved. 

This organism is pathogenic to beans and 
some related legumes and is closely related to 
Ps. hyacinthi and Ps. campestris. The bean 

Fig. 18.— Ps. phaseoli. disease, occasioned by it was noted and as- 
cribed to bacteria by Beach "^ and by Hal- 

sted ^° in 1892, and the organism was described by E. F. Smith 

in 1897 ^^ after it had been grown in pure culture and successful 

inoculations had been made. 




32 THE FUNGI WHICH CAUSE PLANT DISEASE 

Ps. pruni, E. F. Sm. The organism resembles Ps. campestris 
but is distinguislied from it by its feebler growth on potato and 
by its behavior in Uschnisky's solution which it converts into a 
viscid fluid. It consists of small rods, motile by one to several 
polar flagella. T. D. P. 51°. Gelatine not Hquefied. Casein 
slowly precipitated and later redissolved. No gas. 

The bacteria enter through the stomata of the Japanese plum; ^^ 
cause small watery spots on green fruit and leaves, and finally the 




Fig. 19. — Earliest stage of fruit spot on green plums, due to Ps. 
pruni. The bacteria entered through the stoma. After Smith. 



death of the affected tissue. In earliest disease they are limited 
to the substomatal space but gradually they invade more distant 
tissue. Wounds are not necessary to infection. It seems to have 
been seen first on the peach in 1903 by O'Gara in Georgia and in 
the same year by Clinton in Connecticut. Rorer ^^ by numerous 
cultures and cross inoculations proved this same organism re- 
sponsible for a leaf, twig and fruit disease of peaches. In the twig 
the bacteria were present in great numbers in the bast. 

Ps. radicicola (Bey.) Moore.^^ The legume root-tubercle or- 



THE FUNGI WHICH CAUSE PLANT DISEASE 



33 



ganism, by some regarded as a parasite, though beneficial, and by 
others regarded as a mutualistic symbiont will not be discussed 
here owing to its beneficial character. 




Fig. 20. — Part of sweet-corn stem parasitized by Ps. stewarti. After Smith. 



Ps. savastanoi (E. F. Sm.) Stev. A rod with rounded ends, 
solitary or in short chains, 1.2-3 x 0.4-0.8 n; motile; aerobic; non- 
sporing; flagella 1-several, often 2-4, polar. Standard agar, 
surface colonies, white, small, circular, smooth 1.5-3 mm. at three 
days, edge entire; bouillon thinly clouded, precipitate shght, white, 
no rim or pellicle. On gelatine no liquefaction; colonies white, 
round, erose, margin pale. 



34 



THE FUNGI WHICH CAUSE PLANT DISEASE 



From swellings known as olive tubercles on Californian olive 
branches, E. F. Smith isolated this organism ^^ which is in part 
Ps. oleae-tuberculosis and which may bear relation to several other 
olive bacteria previously described in Europe. 

The organism when inoculated by puncture into young olive 
shoots produced the characteristic tubercle. Later it was re- 
isolated from these artificially produced tubercles and used in a 
second series of inoculations which gave a second crop of tubercles. 
Controls showed no infection and healed promptly. The oleander 
was not susceptible to infection. 

Smith's results are not in full accord with much of the European 
work on the olive tubercle. 

Ps. sesami Malk. causes disease on sesame ^^ 
Ps. stewarti, E. F. Sm. A medium size rod, 0.5 - 0.9 /z x 1 - 2 p., 
with rounded ends, and 1 polar flagellum. Buff-yellow to chrome 
or ochre color; non-liquofving; does not separate casein in milk. 

T. D. P. 10 min., 53°. 
Agar colonies subcir- 
cular, becoming lobate; 
bouillon rendered tur- 
bid with yellow-white 
precipitate. No gas. 

The bacterial corn 
blight of this organism 
was first described by 
Stewart in 1897 ^^ and 
attributed to bacteria. 
The organism was de- 
scribed by E. F. Smith 
in 1890 '^s from a cul- 
ture furnished by Stew- 
art. Definite proof by 
inoculation of the 
causal relation of this 
particular organism to the disease was adduced in 1902 by 
sprinkling bacteria upon the leaves.^^' ™ Some plants showed 
typical constitutional symptoms during the first month, most of 
them in two or three months when the plants were several feet 




Fig. 21. — Various forms of Ps. stewarti, gr 
potato agar; a and b are typical forms 
Stewart. 



Aftc 



THE FUNGI WHICH CAUSE PLANT DISEASE 



35 







7 



V 



X/ 



high. In these plants the vessels become plugged with pure cul- 
tures of Ps. stewarti from tip to base. Small holes filled with 
yellow slime appeared later in the parenchyma. Wounds were en- 
tirely unnecessary to infection, though the vessels are the primary 
seat of disease. 

Ps. syringae v. Hall "^ causes disease of Syringa and other plants. 

Ps. tumefaciens (S. & T.) Stev.^-"^^ (Group number 
212.2822023.) Vegetative cells taken directly from a gall usually 
0.6 to 1.0 M X 1.2 to 1.5 IX. 

When grown on agar for two days 2.5 to 3 /x x 0.7 to 0.8 y. or 
occasionally wider. Endospores not observed. Motile by means 
of one, sometimes two or three terminal flagella; viscid on agar 
but capsules not demonstrated. Readily stained in ordinary basic 
anilin stains; Gram negative. Agar surface colonies usually come 
up in from four to six days at 25°, 
white, smooth, circular; margin even, 
shining, semi-transparent, maximum 
size 2 to 4 mm. Agar streak; growth 
moderate, filiform. On sterile potato 
cylinders growth more rapid, in one 
or two days covering the entire surface 
of the cylinder; smooth wet-glisten- 
ing, slimy to viscid, odorless; potato 
cylinder grayish, darker with age, 
never yellow. Gelatine colonies dense, 
white, circular, small, non-liquefying, 
medium not stained. In beef broth 
clouding often absent or inconspicuous, rim of gelatinous threads 
present, also more or less of peUicle; in young cultures very deli- 
cate suspended short filaments, best seen on shaking. Milk coagu- 
lation delayed; extrusion of whey begins only after several days; 
litmus milk gradually blued, then reduced. Cohn's solution, 
growth scanty or absent, medium non-fluorescent. 

No gas produced; organism aerobic in its tendencies; nitrates 
not reduced. Indol produced in small quantity, slowly. Slight 
toleration for citric, malic, and acetic acids. Toleration for alkali 
slight. Optimum reaction between +12 and +24, Fuller's 
scale. T. D. P. 51°. Opt. between 25° and 28° Max. ±37°. Growth 




Fig. 22. 



Flagella of Ps. tumefa- 
ciens, various stains. After 
Smith. 



36 THE FUNGI WHICH CAUSE PLANT DISEASE 

occurs at 0°. Milk, bouillon, dextrose peptone water with calcium 
carbonate are the best media for long continued growth. 

The following are recommended as quick tests for differential 
purposes. Time of appearance of colonies on +15 agar plates 
made from the tumors; young agar stroke cultures; behavior in 
milk and litmus milk; growth on potato; behavior in Cohn's 
solution; stringy ring and suspended filaments in peptonized beef 
bouillon; inoculations into young, rapidly growing daisy shoots 
or into growing sugar-beet roots. 

The organism is readily plated from young sound galls, i. e., 
those not fissured or decayed. 

In galls on the Paris daisy (Chrysanthemum frutescens) these 
bacteria were found in small numbers. By plating they were 
obtained in pure culture and puncture inoculations repeatedly 
resulted in the characteristic gall. From these the organism was 
reisolated and the disease again produced, thus giving conclusive 
evidence that the organism is the actual cause of the gall. Swell- 
ings began four or five days after inoculation and in a month they 
were well developed though they continued to enlarge for several 
months, reaching a size of 2-5 cm. in diameter. 

Tumor-producing Schizomycetes have also been isolated from 
over-growths on plants belonging to many widely separated 
families (Compositae to Salicacese). Natural galls have been 
studied on Chrysanthemum, peach, apple, rose, quince, honey- 
suckle, Arbutus, cotton, poplar, chestnut, alfalfa, grape, hop, beet, 
salsify, turnip, parsnip, lettuce, and willow. The organisms from 
these sources are closely alike on various culture media, and many 
of them are readily cross-inoculable, e. g., daisy to peach, radish, 
grape, sugar-beet, hop; peach to daisy, apple. Pelargonium, 
sugar-beet, poplar; hop to daisy, tomato, sugar-beet; grape to 
almond, sugar-beet; poplar to cactus, oleander, sugar-beet; willow 
to daisy. With eight of these organisms tumors have been pro- 
duced on sound specimens of the species from which obtained. 
Some cross-inoculate more readily than others, and there are also 
slight cultural differences. Thus, it is probable that there are 
several races of the gall-forming organisms varying more or less 
in amount of virulence and in adaptability to various hosts. In 
general it is said that all plants susceptible to crown galls, i. e., 



THE FUNGI WHICH CAUSE PLANT DISEASE 37 

those on which the galls have been found in nature, are susceptible 
to artificial cross inoculation. Hard gall, hairy root, and soft gall 
are also all due to infectious bacteria. 

As tentative hypotheses Smith assumes either: (1) That the 
hairy root organism while resembling the crown gall organism is 
not identical with it; or (2) That they are the same, and that if 
infection takes place in a certain group of cells an ordinary gall 
will develop, while if other special groups of cells are first invaded, 
i. e., the root aniagc, then a cluster of the fleshy roots will develop. 
Some of his inoculation experiments point to the latter conclusion. 

Ps. vascularum (Cobb) E. F. Sm. ^^' ^^' " is parasitic on sugar 
cane, filling the bundles with a yellow slime. It has not been re- 
ported in America. 

Ps. sp. indet. A short rod, 2-4 x 1-1.5 m,- actively motile by 
1-3 polar flagella, was isolated from diseased spots on the larger 
veins and petioles of beet leaves by Brown."^ The organism was 
successfully inoculated in pure culture, disease produced, and the 
organism reisolated. It is infective as well for lettuce, sweet 
pepper, nasturtium, egg plant and bean. Agar colonies are creamy 
white, thin, circular, turning the surrounding agar yellow-green 
in three days. Gelatine is liquefied; litmus milk turns blue; 
bouillon is clouded. Opt. 28°. 

Ps. sp. indet. A short rod, 2^ n long, motile by 1-3 polar 
flagella was isolated from diseased nasturtiums (Tropeolum) 
leaves by Jamiesson.^° Pure culture inoculations induced typical 
disease. The organism clouds bouillon; produces on agar small, 
round, bluish- white colonies; liquefies gelatine and does not pro- 
duce gas. Opt. 25°. T. D. P. 49-50°, 10 min. It is pathogenic 
also for sweet-pea, lettuce, pepper, sugar-beet and bean. 

Bacillus Cohn. (p. 18.) 

This genus differs from Pseudomonas only in its peritrichiate, 
not polar, flagella. Endospores are often present. Of the four 
hundred and fifty or more species nineteen at least are known to 
be plant pathogens. Numerous animal pathogens also belong to 
this genus, notably B. typhosus, B. pes'is. 

B. ampelopsorae Trev. is said to cause grape galls in Europe, 
but the evidence is by no means conclusive. Cf. B. uvae. 



38 



THE FUNGI WHICH CAUSE PLANT DISEASE 




Fig. 23. — B. amylo- 
V o r u s, multiply- 
ing by fission. 
After W h e t z e 1 
and Stewart. 



B. amylovorus (Burr.) De Toni. (Group number 221. — .) 

Bacillus in broth, 0.9-1.5 x 0.7-1.0 y., longer when older. 
Gram positive; no capsule; flagella several; no spores; broth 
clouded, pellicle slight. Gelatine shows slow, crateriform lique- 
faction. Agar, buried colonies white, surface 
colonies elevated, circular wet-shining, margin 
irregular. Milk coagulated in three-fourths of 
a day, later digested to a pasty condition. 
Opt. 25-30°. T. D. P. 43.7°, 10 min. Faculta- 
tive anaerobe. Indol produced; no gas; no pig- 
ment. 

Bacteria were noted in blighted pear twigs by 
Burrill in 1877.8-' ^^ In 1880 he ^^ demonstrated 
the communicability of the disease by intro- 
ducing the bacterial exudate into healthy pear 
trees as well as into apple and quince trees. 
This constitutes the first case of plant disease definitely at- 
tributed to bacteria. Burrill's results were confirmed by Arthur 
in 1884 8^ by one hundred and twenty-one puncture 
inoculations, using the exudate, also a bacterial 
suspension from diseased twigs. He further demon- 
strated the susceptibility of Juneberry and haw- 
thorn. Usually the disease appeared about a 
week after inoculation. Attempted raspberry and 
grape inoculations failed. 

Arthur placed the whole matter on a firm foun- 
dation by passing the bacteria through a long 
series of artificial cultures and then by inocula- 
tions, showing that they were capable of causing 
the blight.8^' ^"^ He further demonstrated that the 
bacterial exudate from the tree, when freed of 
bacteria by filtration, could not produce disease. 
The results of an extensive study of the bacteria on 
various media; of their morphology and stain 
reactions were published by Arthur in 1886.^^ Bacteria were 
shown to penetrate twigs 3-4 dm. beyond their area of visible 
effect. 207 

In 1902 Jones ^^ isolated an organism from blighted plum trees. 




Fig 



24.— Claw 
from bee's foot 
with blight 
bacteria on 
and about it 
showing the 
relative size. 
After Whct- 
zel and Stew- 
art. 



THE FUNGI WHICH CAUSE PLANT DISEASE 39 

This he demonstrated by culture and cross inoculation in fruits to 
be identical with the pear blight organism, though inoculations in 
plum twigs did not give disease, presumably due to the high re- 
sistance of this plant. Similarly Paddock has shown this organism 
to attack the apricot.^° Detmers has reported what she regarded 
as this blight caused by this Bacillus on blackberries.^^ 

Other hosts are hawthorn, shad bush, mountain ash. 

By inoculations with pure cultures of the apple body-blight 
bacteria, blight upon twigs and blossoms was produced by Whetzel 
in 1906,^" thus proving the identity of these two forms of disease, 
an identity asserted first by Burrill.^^ 





Fig. 25. — B. aroideae. After Townsend. 

B. apii (Brizi.) Mig.^'* is reported as the cause of a celery rot, 
which is possibly identical with a bacterial rot reported earlier 
by Halsted.*^^ 

B. araliavorous Uyeda, described on Ginseng in Korea is per- 
haps also the cause of soft rot of Ginseng in America.^^ The 
organism was isolated and studied by Uyeda who made inocula- 
tions. 

Pseudomonas araliae and Bacillus koraiensis were also com- 
monly present in the Oriental disease.^^ 

B. aroideae Town. (Group Number 221.2223022.) =^=^ 

This organism was described in 1904 as the cause of soft rot of 
calla ^^ corms and leaves. The bacteria were present in almost 
pure culture in affected tissue and by puncture inoculation in pure 
culture produced the typical disease in a few days. 

Townsend regarded the organism as distinct from B. carotov- 
orus, B. oleracese, B. hyacinthi septicus and Pseudomonas de- 



40 



THE FUNGI WHICH CAUSE PLANT DISEASE 



structans. Harding and Morse, however, believe it specifically 
identical with B. carotovorus. See p. 42. 

B. atrosepticus v. Hall,^^ was isolated from ducts of potatoes 
affected with black leg. 

B. avenae, Manns.^^ This is the symbiont of Pseudomonas 
avense. See p. 23. 

(Group number 222.2223532.) A very actively motile bacillus, 
short, rod-shaped with rounded ends, 0.75 to 1 x 1.5 to 2 /i. 




Fig. 26. — Plate culture of B. avenae, on nutrient glucose agar, 
four days at SCC. After Manns. 

Gram negative; endospores not observed; flagella many, diffuse, 
long, undulate; growth on agar stroke rapid, filiform, white, 
glistening, later somewhat dull, margin smooth, growth rather 
opaque, turning yellow third day; gelatine not liquefied; broth 
clouded and on the second day showing heavy yellow precipitate; 
milk coagulated at end of two weeks with extrusion of whey; 
agar colonies round, entire, surface smooth, slightly raised. No 
gas in dextrose, saccharose, lactose, maltose, or glycerins. Indol 
production moderate; nitrates reduced to nitrites. T. D. P. 10 
min., 60°; Opt. 20-30°. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



41 



B. betas Mig. is reported as the cause of gummosis of beet.^"*^ 
B. brassicaevorus Del, isolated from diseased cabbage ^°^ is per- 
haps identical with Pseudomonas fluorescens. See page 27. 

B. carotovorus Jones. (Group number 221.1113022.) From 
agar 1-2 days old as 
short or long rods, in 
short or long chains. 
0.7-1.0 X 1.5-5 n, com- 
monly 0.8 X 2 ju; ends 
rounded. No spore; 
flagella 2-10, peritri- 
chiate; no capsule; 
Gram negative. White 
on all media. Agar 
slope filiform to spread- 
ing, glistening, opaque 
to opalescent. In gela- 
tine stab; liquefaction 
crateriform to infun- 
dibuliform. Broth 
clouded, peUicle thin 
to absent, sediment 
flocculent; milk coagu- 
lated. Agar colonies, 
round, smooth, entire 
to undulate, amor- 
phous or granular. Fig. 27. — B. cmotovuruis wedging apart cells of the 
. carrot. After Smith. 

bome gas m dextrose, 

lactose and saccharose, nitrates reduced to nitrites; indol feeble. 

T. D. P. 48-50°. Opt. 25-30°. 

A considerable number of cultivated plants suffer soft rot from 
the attacks of a non-chromogenic liquefying bacillus. Among the 
plants so affected are cabbage, turnips and other crucifers; parsnip, 
carrot, mangel, sugar-beet, potato, celery, tomato, Jerusalem 
artichoke, asparagus, rhubarb, onion and iris. 

In 1901, Jones reported an organism isolated from rotting carrots 
which he named B. carotovorus. ^°-' ^°^ It disorganized tissue 
by solution of the middle lamella; and infection into wounds led 







42 THE FUNGI WHICH CAUSE PLANT DISEASE 

to decay of roots of carrot, parsnip, turnip, radish, salsify, of 
onion bulbs, hyacinth corms, cabbage heads, celery stalks and 
fruits of tomato, pepper and egg plant. Jones found no decay pro- 
duced in young carrot or parsnip plants, fruits of orange, banana, 
apple, pear, cauliflower head,* Irish potato tuber, beet root or 

tomato stems. ^°^ Infection 
v. ^J ^__^ did not occur unless the 
-^ "* "^ epidermis was broken. The 

rotten mass was always 
soft, wet, and exuded a 
liquid clouded with bac- 
teria. 

Jones ^^ in 1909 made an 
. , , extensive study of the cyto- 

biG. 2S. — B. carotovorus. Alter Jones. . . 

litic enzyme of this germ. 
This enzyme was separated by heat, filtration, formalin, phenol, 
thymol, chloroform, diffusion, alcohol, and its conditions of pro- 
duction and action investigated. Heating the enzyme to 60° in- 
hibited its activity to a marked degree; higher than 63° inhibited 
it entirely; chloroform, thymol and phenol did not retard its ac- 
tion. No loss was suffered through alcoholic precipitation and 
resolution. The dried enzyme remained active for fully two 
years. Its effect was greatest at 42°, less at 32° and 48°. No 
diastatic action was observable. 

In 1909 Harding and Morse, ^^ from an extended study of some 
12,000 cultures of non-chromogenic, liquefying soft-rot bacilli 
of some forty-three pathogenic strains (including B. carotovorus, 
B. oleraceae, B. omnivorus, B. aroideae and what Potter regarded 
as Pseudomonas destructans), from six different vegetables, con- 
clude that unless later studies of the pathogenicity of these cul- 
tures shall offer a basis for subdividing them, there is no apparent 
reason why they should not all be considered as somewhat variant 
members of a single botanical species. 

This conception would lead to the abandonment of the supposed 
species mentioned above and the recognition of all of them under 
their oldest described form, B. carotovorus Jones, which in our 

* Harding and Stewart later showed that it is capable of rotting cauli- 
flower. 



THE FUNGI WHICH CAUSE PLANT DISEASE 43 

present knowledge seems certainly to be the most wide spread, 
common and destructive of the soft rot bacteria. Some, perhaps 
much, of the rot of crucifers generally thought to be due to Pseudo- 
monas campestris is probably caused by B. carotovorus. See 
Harding & Morse.^^ 

B. caulivorus, Pril. & Del. has been reported as the cause of 
spots on grapes under glass, also as a parasite on a large number 
of other plants among them Pelargonium, potato, begonia, clem- 
atis. It is later stated that this is probably really a variety of 
Ps. putrifaciens liquefaciens. 

B. cepivorus Del. (possibly a Bacterium) is recorded on onion 
bulbs.^i 

B. coli (Esch.) Mig. or an organism indistinguishable from it is 
held by Johnston ^^^ capable of causing rot of soft tissues of the 
cocoanut plant and is perhaps responsible for cocoanut bud 
rot. 

B. cubonianus Mace, was originally described as the cause of 
mulberry disease (cf. Ps. mori). This organism, or at least one 
that was regarded as indistinguishable from it, has been men- 
tioned as the cause of a disease of hemp.^*^^ 

B. cypripedii Hori is a medium sized slender, non-sporulating 
form with four flagella.-'^^ 

B. delphini E. F. Sm. This is a motile, gray-white, nitrate- 
reducing, non-liquefying organism. On agar young colonies small, 
circular, wrinkled. Grows well at 30°, not at all at 37.5°. T. D. 
P. 48^9.1°. 

The cause of stomatal infection of larkspur resulting in sunken 
black spots on leaves and stems. ^''^ 

B. elegans Hegyi is reported on lupine. ^"'^ 

B. dahliae Hori & Bakis is on dahUa.^^^ 

B. gossypini Stedman was reported by Stedman ^°^ as the 
cause of cotton-boll soft rot in Alabama; much doubt, however, 
remains as to its actual identity and causal relation. It was de- 
scribed as a short, straight, spore-forming motile bacillus; 1 .5 x 
.75 fx; aerobic; non-liquefying (?). 

B. gummis Comes, has by some been held responsible for gum- 
mosis or inal nero of the grape vine ^"^ though others discredit this 
idea. 



44 



THE FUNGI WHICH CAUSE PLANT DISEASE 



B. haria Hori & Miy. is a parasite of the Japanese basket 
willow. '^^ 

B. hyacinthi septicus Heinz, ^-^ is recorded as the cause of a soft 
white rot of the hyacinth. 

B. iactucae Vogl. is said to cauee a lettuce disease. ^^^ 
B. lycopersici Hegyi has been described as the cause of a rot 
of tomatoes. ^^- 

B. maculicola Del. is regarded as the cause of a tobacco leaf 
spot.^^^ 

B. melanogenus P. & M.^^^is recorded in England on potatoes. 
B. melonis Giddings.^^^ 

An actively motile bacillus, 0.6-0.9 x 1-1.7 fx; flagella 4-6 
peritrichiate; no spores. Gram negative. Broth strongly clouded, 

no pellicle or ring, 
slight sedim.ent. Agar 
stroke slimy, glistening 
translucent; colonies 
round or amoeboid. In 
gelatine stab liquefac- 
tion infundibuliform in 
two days. Milk co- 
agulated with abun- 
dant gas. Nitrite pro- 
duction abundant ; indol 
slight. T. D. P. 49- 
50°. Opt. 30°. The 
vegetables rotted were 
muskmelon, citron, car- 
rot, potato, beet, cu- 
cumber and turnip. 

In the soft rot caused 
by this organism in 
muskmelons, motile 
bacteria were observed in abundance by Giddings in 1907. Plating 
gave pure cultures which by inoculation tests were shown to be 
those of the causal organism of the rot. Decay is produced by 
solution of the middle lamella by enzymic action, the remainder 
of the walls withstanding the attack. The bacteria are thus 




Fig. 29. — Photomicrograph of B. melonis. a, show- 
ing living organisms in agar hanging block cul- 
ture; b, with flagella stained by Lowitz method. 
After Giddings. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



45 



strictly intercellular. Wound inoculations in muskmelon generally 
gave complete decay in from three to seven days. Similar inocula- 
tion of citron and cucumbers resulted in decay, though inoculation 
into squash did not. No decay of musk- 
melon followed applications of the bacteria 
to unbroken surfaces. 

B. mycoides Fliigge. (Group number 
-22.1 8-.) 

Rods thick, 0.95 x 1.6-2.4 ^u, usually in 
long threads, sporiferous. Spores elliptical, 
1.3-1.48 X 0.7-0.9 mm. Gelatine colonies 
white with mycelium-like outgrowths; gela- 
tine liquefied. Pellicle formed in broth. 
Gram positive. 

This common soil organism has been held 
responsible for a disease of beets. ^^^ 

B. nicotianae Uyeda is ascribed as the 
cause of a tobacco wilt in Japan ^^'^' ^^^ which 
closely resembles that caused by B. sola- 
nacearum in America. 

The bacillus is 1-1.2 x 0.5-0.7 ix with 
rounded ends, actively motile by peritri- 
chiate flagella. Spores are produced. A 
complete physiological study is to be found 
in the articles above cited. 

Bacillus oleae (Arc.) Trev. (Group num- 
ber -22.333-0—.) C. 0. Smith describes 
the organism as a motile rod with rounded 
ends, 1.5-2.5 x 0.5-0.6 ix. On agar slant 
growth thin, gray-white, spreading; colonies 
circular, whitish. On gelatine no liquefac- 
tion. Milk not coagulated. Distribution of 
flagella not stated. 

In oleander tubercles on leaves and twigs, 
and in oUve tubercles C. O. Smith ^^^ found 
bacteria which he regards as this species. Upon puncture inocu- 
lation in both olive and oleander, tubercles were produced. Con- 
trols were not diseased. The organism was reisolated from the 




Fig. 30.— Cultures of B. 
melonis on silicate jelly 
slants, 12 da3^s' growth, 
(30° C.) After Gid- 

dings. 



46 THE FUNGI WHICH CAUSE PLANT DISEASE 

artificially produced knot with unchanged characters. E. F. 
Smith's results ®^ do not agree with those of C. O. Smith. (See 
Pseudomonas savanastoi.) 

B. oleraceae Harr. (Group number 221.1113022.) 120-122 

This organism was studied by Harrison in 1901 in Canada where 
it was found associated with a soft rot of cauliflower, cabbages and 
turnips. In the rotting tissue it was always present; it was iso- 
lated, and upon inoculation and cross inoculation characteristic 
infection followed. The organism was reisolated in unchanged 
character. The chemical products of the bacillus, secured by 
filtration, also produced the characteristic tissue changes. Sec- 
tions of diseased tissue showed the bacteria in the intercellular 
spaces, occupying the position of the middle lamella which was 
softened and eventually dissolved by the bacterial enzymes. 

Harding and Morse ^^ from their extensive studies conclude 
that this form is identical with B. carotovorus. See p. 42. 

B. omnivorus v. Hall is described by van Hall ^^^ as the cause of 
a soft rot of iris shoots and rhizomes. According to Harding & 
Morse ^^ it does not present characters sufficient to distinguish it 
from B. carotovorus. See p. 42. 

A species closely related to B. omnivorus is described by Uyeda ^^'^ 
as the cause of a disease of Zingiber. The organism was isolated and 
studied and the disease produced by inoculation with pure culture. 

B. oncidii (Pegl.) Stev. is mentioned ^^^ as the cause of an 
orchid leaf spot. 

B. oryzae Vogl. has been mentioned as the possible cause of 
brusone ^"^ of rice. 

B. phytophthorus Appel. (Group number 221.21230—.) A 
non-sporiferous rod, 0.6-0.8 x 1.5-2.5 fx, actively motile by per- 
itrichiate flagella. Gram negative. It rots potatoes, cucumbers, 
etc.; is aerobic or a facultative anaerobe; grayish white on agar; 
surface colonies round, smooth; gelatine liquefaction moderate; 
bouillon clouded; no indol; no gas. Nitrate changed to nitrite. 
Milk coagulated and casein precipitated. Opt. 28-30°. T. D. P. 47°. 

It was described by Appel ^-'^ of Berlin as the chief cause of 
potato black-leg. The description given above is by E. F. Smith ^'^ 
and was made from Appel's organism. Smith also isolated it from 
potatoes grown in Maine and in Virginia. 



THE FUNGI WHICH CAUSE PLANT DISEASE 47 

It is closely related to but is not identical with B. solanisaprus 
and B. atrosepticus.^-^ 

B. populi Brizi is said to cause galls on the poplar ^-^. 

B. pseudarabinus R. G. Sm.^'^'^ is capable of producing on inocu- 
lation a crimson-red gum in the vessels of sugar cane and is per- 
haps responsible for a disease showing this symptom. 

B. rosarum Scalia is the name given to a very imperfectly 
described organism said, on scant evidence, to be the cause of rose 
tumors or crown galls /^ 

B. sesami Malk.^^ Malkoff in infection experiments caused a 
disease of sesame with this organism. 

B. solanacearum E. F. Sm. (Group number 212.333-8—.) 
A medium sized, easily stained, strictly aerobic bacillus with 
rounded ends; about lJ^-3 times longer than broad; 0.5 x 1.5 /x. 
Motile, sluggish or active; flagella long, diffuse. Spores not 
known. Zoogloea occur in liquid media as small, white flecks or 
as surface rings. It grows well at 20-30°. Milk is saponified with 
no casein precipitation or acidity. Gelatine not liquefied. Agar 
surface colonies, dirty-white. Agar streaks first dirty- white, later 
yellowish to brownish-white, then brown. On potato as on agar, 
but darker, with substratum and fluid browned. No gas from 
cane sugar, lactose, maltose or dextrose. 

The disease caused by this bacillus upon tomato and other 
plants was early studied by Halsted i^i-iss qj^^ perhaps by Bur- 
rill. ^^'^'^^^ Halsted made inoculations which produced the disease 
but he did not use pure cultures. The first complete account of 
the causal organism was given by E. F. Smith ^^^' ^^^ in 1896. 

In its hosts the bacillus is found in the pith, in the xylem which 
is browned, and more rarely in the bark. From the cut ends of in- 
fected ducts bacteria exude as a viscid ooze and the diseased ducts 
may be traced to great distances through the plant, even from root 
to leaf. From the bundles the organism later invades other tissues. 

Needle prick inoculations in tomatoes and potatoes with pure 
cultures, were followed after several weeks (tomato) by typical 
disease. Inoculations in Irish potato resulted similarly, though in 
this host the parenchyma and bark were eventually invaded, and 
the tuber was reached through its stem end and rotted. In South 
Carolina, Smith noted the disease on egg plants and crude cross 



48 



THE FUNGI WHICH CAUSE PLANT DISEASE 



inoculations were made to tomato. Smith demonstrated experi- 
mentally the efficiency of the potato beetle in transmitting the 
disease. 

The disease was described for tobacco by Stevens ^^^ and Stevens 
and Sackett.139 

Successful inoculations were reported upon tobacco by E. F. 
Smith in 1909 ^'° though in his earlier trials tobacco and pepper 
gave negative results when inoculated with this bacillus. In addi- 
tion to the above hosts it is known to grow upon Datura, Solanum 
nigrum, Physalis and Petunia. 

B. solanicola Del. was reported as the cause of a potato stem 
disease. ^^^ 

B. solaniperda Mig. (Group number 121. 0--.) A rod, 

2.5-4 X 0.7-0.8 li, with rounded ends, often in long chains; actively 
motile ; spores present. Agar colonies dirty-white ; gelatine liquefied. 
This was shown by Kramer in 1890 ^^^ to be the cause of soft rot 

of potatoes. The organism 
was grown in pure culture 
and inoculated on potatoes 
producing the characteris- 
tic decay. The germs enter 
through the lenticels, con- 
sume the sugar, then at- 
tack the intercellular sub- 
stances and the cell wall. 
Later the albuminous sub- 
stances are destroyed. 

B. solanisaprus Harr. 
(Group number 221.212-0- 

_ \ 143 

Fig. 31.— Surface colonies of B. solanisaprus. A bacillus with rounded 

After Harrison. , ^ ^ . ^ „ 

ends, 1.5-4 x 0.6-0.9 n, 
variable in culture; no capsule; actively motile by 5-15+ peritri- 
chiate flagella; no spores seen. Gram negative. Gelatine colonies, 
punctiform 0.25 mm. at two days ; gelatine stab filiform. Liquefac- 
tion noticeable on the thirty-fifth day. Agar colonies punctiform 
at two days, 1-5 mm., gray-white, slimy, flat. Bouillon turbid 
with fine sediment; ring, and thin band present; milk curdled. 




THE FUNGI WHICH CAUSE PLANT DISEASE 49 

Gas only in mannite and lactose. Nitrate reduced to nitrite. 
Opt. 25-28°. T. D. P. 54°, 10 min. 

It was found constantly associated with a type of potato disease 
which Harrison regarded as distinct from black-leg and from the 
disease caused by B. 
solanacearum. It was 
repeatedly isolated 
from diseased tubers, 
stems and leaf veins 
and occurred in prac- 
tically pure culture in 
freshly infected tissue. 

The organisms first 
appeared in the ducts 
and thence invaded 
the surrounding tis- 
sue, dissolving the 
middle lamellse and 
producing cavities. 
Inoculations of pure 

cultures into healthy Fig. 32.— B. solanisaprus, from agar 24 hours. 
. , After Harrison. 

plants produced char- 
acteristic lesions and the organism was reisolated. Characteristic 
enzymic action was observed on placing precipitated enzyme on 
slices of potato. 

B. sorghi Burr."4 Rods 0.5-1 (usually 0.7) x 1-3 (usually 
1.5) fi, cylindrical or oval, motile, spore-bearing, non-liquefying. 
Colonies on agar, white to pearly. In broth with a white smooth 
membrane. 

The bacillus was recognized as the cause of a sorghum blight 
by Burrill and this view was confirmed by Kellerman & Swingle 
through ^^'^ inoculation experiments. 

B. spongiosus A. & R. ^^^ causes gummosis of cherry in Ger- 
many. 

B. subtilis (Ehr.) Cohn. 

Straight rods, often united in threads, 0.7 x 2-8 jj,. Sporiferous. 
Spores central or lying near one pole; germination equatorial. 
Flagella, 6-8, peritrichiate; gelatine liquefied; gelatine colonies 




50 



THE FUNGI WHICH CAUSE PLANT DISEASE 



bordered by numerous fine filamentous outgrowths. Growth on 
slant agar gray. It is reported as the cause of vegetable rot.-^''^ 




B. tabacivorus Del. is recorded on tobacco stems. 
B. tabificans Del.^'^ which perhaps belongs to the genus Bac- 
terium is reported as the cause of a beet disease in France. 
B. tracheiphilus, E. F. Sm. (Group number 222. 03-.) 



THE FUNGI WHICH CAUSE PLANT DISEASE 51 

Bacillus 1.2-2.5 x 0.5-0.7 n, variable, actively motile in young 
cultures. Capsulated, no spores, peritrichiate. No gelatine 
liquefaction. On agar thin, smooth, milk-white. No gas, aerobic 
or facultative anaerobic. Milk not curdled. T. D. P. 43°, 10 min. 

This pathogen was first reported by E. F. Smith without de- 
scription in 1893 ^^^ and more fully in 1895.^^° It is found filling 
the vessels of cucurbits, (musk melons and cucumbers) affected 
with wilt. Smith produced the disease artificially by puncture 
inoculations on the blades of leaves with the white sticky fluid 
from infected veins. The inoculated plants showed symptoms of 
wilt after four days and sixteen days later the ducts of the vine 
were found to be plugged with bacteria. The organism was then 
isolated from this artificially infected plant. The cultures thus 
obtained were carried by transfers over winter and in December 
were used successfully to 
infect cucumber plants. 
Control plants were never 
diseased. The ready 
growth of the organism in 
the vessels is attributed to 
the alkalinity of the latter; 
the failure to grow in the 
parenchyma is attributed 
to its acidity. 

B. uvae Cug. & Mac. is ''j^^*"C'l. ^' . C'V"**- 
reported as causmg mjury ^j*, t** ^ s, "jl C* * *'\r' 
to young grape clusters.'' 
It is perhaps identical with 
B. ampelopsorae. m>^ >•" ^'' ** »r*', '*' '^'^i 

B. vulgatus (Flugge) -J >. ^''^^^^ "'^'. /. .>-/ ' 
Mig. This organism is *"' A ' " V,." X -/ ^x^l/,0 ' 

found as small thick rods ^^^ ^^_^ tracheiphilus. ^Ifter Smith. 

with rounded ends, or is 

often paired or in chains of four; sporiferous. Gelatine colonies 

round, hquefaction rapid. Growth on agar dirty-white. 

It has been shown capable of causing rot of various vegetables. ^^' 
B. zeae Burr, is the name applied to a bacillus isolated from 

diseased corn plants by Burrill in 1887-1889.^^''* ^^^ It is often 




ury .^, tj. a, ^ir^:-' \\r . 

,151 - . ^3»,'A * >^n«''w\<V' • ' 



52 THE FUNGI WHICH CAUSE PLANT DISEASE 

cited as the cause of a bacterial corn disease but the evidence of 
causal relation as well as the identity of the germ are not clear. 

B. zinzgiberi Uyeda causes a disease of Zinzibar,-°*^ B. sac- 
chari and B. glangae are on sugar cane as the possible cause of 

, 58 

sereh. 

An organism called Clostridium persicae-tuberculosis by 
Cavara ^^^ is mentioned as cause of knot on peach trees. 

Less known bacterial plant diseases. The literature abounds 
in references to what are regarded as cases of plant bacteriose, 
cases which as yet rest upon very incomplete evidence. In many 
of these bacteria are found in abundance in the diseased tissue 
but pathogenicity has not been proved by inoculation nor pure 
cultures made. Among such incompletely studied diseases may 
be mentioned those of geranium; I'^^-iss celery /^^ onion, ' 
cucumber, ^^^ orchard grass, ^^^ lettuce, ' (one lettuce disease 
is due to a motile rod-shaped organism cultured and inoculated 
but not named, ^^^) strawberries, ^^^"^^^ mulberry, ^^^ hemp,^^" calceo- 
laria.^^^ 

There are also several obscure bacterial beet diseases; another 
cabbage rot due to Pseudomonas; ^^^ a decay of apples said by 
Prillieux to be due to a Bacillus; ^^^ the blossom-end-rot of tomatoes 
which is perhaps bacterial; ^^"^ a cyclamen leaf spot; ^^^ a juniper dis- 
ease; ^'^ a pine gall; ^^" an ash bark disease; ^^^ and an ash canker; ^^^ 
an ivy canker; ^^° a grape disease; a salsify rot; ^^^ a carnation 
spot; ^^^ and a banana disease; ^^^ a gummosis of tobacco; ^^^ a 
disease of tobacco seedlings; ^^^ also perhaps the serious widespread 
mosaic disease of tobacco and an orchid gummosis. ^^ 



BIBLIOGRAPHY OF INTRODUCTION 
MYXOMYCETES AND BACTERIA * (pp. 1 to 53) 

1 Eycleshymer, A. C, Journ. Myc. 7; 79, 1892. 

2 Nawaschin, S., Flora 86: 404, 1890. 

> Woronin, M., Jahrb. f. wiss. Bot. 11: 548, 1878. 

* Rowazek, S., Arb. d. Kais. Gesund. Berlin S2: 396, 1905. 
» Maire, R., & Tison, A., Ann. Myc. 7: 226, 1909. 

' Idem., 9: 226, 1911. 

' Kirk, T. W., D. Agr. R., N. Zeal., 365, 1906. 
8 Viala & Sauvageau, C. R. 11 4: 1892 and 120. 
^Idem., C. R., 115: 67, 1892. 

10 Massee, G., Ann. Bot. 9: 95. 

11 Abbey, Jour. Hort. Soc. London, 1895. 

12 Debray, Rev. d. Viticulture, 85, 1894. 

1' Behrens, J., Weinbau u. Weinhandel, 33, 1899. 

'^ Ducomet, V., C. R. Ass. Fr. Avanc. Sc. Angers, Pt. 2: 697, 1903. 

15 Maublanc, C., Agr. Prat. Pays Chauds. S.- 91, 1908. 

i» Osborne, T. G. B., Ann. Bot. 25: 271, 1911. 

" Lagerheim, Jour. Myc. 7: 103, 1892. 

18 Johnson, Sci. Proc. Roy. Dublin Soc. N. S. 12: 165, 1909. 

* In the bibhographies the usual abbreviations for the states followed by 
B. or R. indicate respectively Bulletin or Report of the State Agricultural 
Experiment Station, B. P. I. or V. P. P. of the Bureau of Plant Industry or 
Division of Vegetable Physiology and Pathology of the United States De- 
partment of Agriculture, respectively. 

Zeit.=Zeitschrift flir Pflanzenkrankheiten. 
Sc."= Science New Series. 
E. S. R.=Experiment Station Record. 
Ann. Myc. = Annales Mycologici. 
Soc. M. rr.=Societe Mycologique de France. 
Y. B. = Yearbook, U. S. Department of Agriculture. 
C. R. = Compt. Rendu. 

C. Bak. = Centralblatt f. Bakt. Par. u. Inf. Ab. II. 
Other abbreviations are those usually employed or readily understood. 
All bold face references,®**" will be found in the book bibliography, page 678. 

53 



54 THE FUNGI WHICH CAUSE PLANT DISEASE 

'9 Johnson, Econ. Proc. Roy. Dublin Soc. 1, pt. 12, 1908. 

20 Wulff, T., Zeit. 16: 203, 1906. 

21 Mangin, L., Rev. Hort. Paris 81: 568. 

22 Zeit. 13: 267, 1903. 

23 Toumey, Ariz. B. 33. 

2" Prillieux, E., Ann. Sc. Nat, 6 ser. 7: 248, 1879. 
25 Frank, Ber. d. Deut. Bot. Gas. 16: 237, 1898. 
20 Frank, C. Bak. 5: 98, 1899. 

27 Roze, E., C. R. 1S2: 543, 1896 and 1S3: 1323. 

28 Delacroix, G., Maladies d. PI. Cult. 19, 1909. 
23 Metcalf, H., Neb. R. 17: 69, 1904. 

• 30 Vuillamen, C. R. 107: 874, 1888. 

31 Busse, W. & V. Faber, F. C., Mit. K. Biol. Anst Land u Forst, 
18, 1907. 

32 Jones, L. R., N. Y. (Geneva) T. B. 11: 1909. 

33 Harding, H. A., and Morse, W. J., N. Y. (Geneva) T. B. 11: 1909. 
3« Smith, E. F., V. P. P. 38: 1901. 

3fi Manns, T. F., 0. B. SIO: 1909. 

36 Pammel, L. H., la. B. 27: 1895. 

37 Russell, H. L., Wis. B. 65: 1898. 

38 Smith, 'E. F., B. P. I. 29: 1903. 

39 Smith, E. F., C. Bak. 3: 284, 485, 1897. 

« Harding, H. A., Stewart, Y. C, and Prucha, M. S., N. Y. (Geneva) 
B.251: 1904. 

*i Garman, H., Ky. R. 3: 43, 1890. 

*2 Harding, H. A., C. Bak. 6: 305, 1900. 

" Potter, M. C., C. Bak. 7: 282, 1901. 

" Jones, L. R., C. Bak. U: 257, 1905. 

« Arthur, J. C. & BoUey, H. L., Ind. B. 59: 17, 1896. 

^6 Barlow, B. B., Ont. Ag. Co. B. 136: 1904. 

« Griffon, E., C. R. Acad. Sci. Paris 149: 50, 1909. 

*^ Scalia, Agricolt Calabro-Siculo, 1903. 

« Smith, E. F., V. P. P. 26: 1901. 

5" van Hall, C. J. J., Zeit. 13: 129, 1903. 

51 Pierce, N. B., Bot. Gaz. 31: 272, 1901. 

" von Oven, E., C. Bak. 16: 1907. 

" Osterwalder, A., Cent. Bak. 25: 260, 1910. 

54 Sackett, W. G., Colo. B. 158: 1910. 

55 Smith, E. F., Sc. 31: 794, 1910. 

59 Boyer & Lambert, C. R., Paris 117: 342, 1893. 
57 Smith, E. F., Sc. N. S. 31: 792, 1910. 



BIBLIOGRAPHY OF INTRODUCTION 55 

"*« Macchiati, L., Malpighia 5: 289, 1892. 

^^ Beach, S. A., N. Y. (Geneva) B. 48: 331, 1892. 

60 Halsted, B. D., N. J. R. 13: 283, 1892. 

«i Smith, E. F., Proc. A. A. A. S. 288: 1897. 

«" Smith, E. F., Sc. 17: 456, 1903. 

63 Rorer, J. B., Mycoligia 1: 23, 1909. 

" Pierce, G. P., Proc. Cal. Acad. Sc. 3rd Ser. Bot. 2: 295, 1902. 

65 Smith, E. F., B. P. I. 131: 25, 1908. 

66 Malkoff, K., C. Bak. 16: 664, 1906. 

67 Stewart, F. C, N. Y. (Geneva) B. 130: and R. 16: 401, 1897. 

68 Smith, E. F., Proc. A. A. A. S. 422: 1898. 

69 Smith, E. F., C. Bak. 10: 745, 1903. 
^° Smith, E. F., Sc. 17: 458, 1903. 

71 van Hall, C. J. J., Bij. t. Kenn. Bak. Plonet 142, 1902. 

72 Smith, E. F., and Townsend, C. 0., Sc. 25: 672, 1907. 
7' C. Bak. 20: 89. 

7" Townsend, C. 0., Sc. 29: 273, 1909. 

76 Smith, E. F., Phytopathology 1: 7, 1911. 

76 Smith, E. F., Brown, N. A., and Townsend, C. 0., B. P. I. 213, 1911. 

77 Cobb, N. A., New So. Wales, Dept. Agr. 1893. 

78 Smith, E. F., C. Bak. 13: 726, 1905. 
'^ Brown, Nellie A., Sc. 29: 914, 1909. 

8" Jamiesson, Clara 0., Sc. 29: 915, 1909. 

81 Delacroix, G., Ann. Inst. Nat. Agi-on. 2, Ser, 5: 353, 1906. 

82 Burrill, T. J., Trans. 111. Hort. Soc. 114, 1877. 
8» Idem, 80, 1878. 

8" Burrill, T. J., Proc. A. A. A. S. 29: 583 and Am. Nat. 15: 527. 

85 Arthur, J. C, N. Y. (Geneva) R. 3: 1884. 

86 Arthur, J. C, Proc. A. A. A. S. 34: 1885. 

87 Arthur, J. C, Bot. Gaz. 10: 343, 1885. 

88 Arthur, J. C, Proc. Phila. Acad. Science 331, 1886. 

89 Jones, L. R., C. Bak. 9: 835, 1902. 
9« Paddock, W., Col. B. 84. 

» Detmers, F., 0. B. Ser., IV: No. 6, 129, 1891. 
»2 Whetzel, H. H., N. Y. (Cornell) B. 236, 1906. 
93 Burrill, T. J., Trans. 111. Hort. Soc. 147, 1881. 
9^ Brizi, U., C. Bak. 3: 575, 1897. 

95 Halsted, B. D., N. J. B. Q: 1892. 

96 Rankin, W. H., Special Crops. N. S. 9: 94, 356. 
"7 Uyeda, Y., see 96. 

98 Townsend, C. 0., B. P. I. 60: 1904. 



56 THE FUNGI WHICH CAUSE PLANT DISEASE 

99 van Hall, C. J. J., Diss. 1902. 
o" Busse, W., Zeit. 7; 65, 1897. 
" Delacroix, C. R. l^O: 1356, 1905. 
02 Jones, L. R., C. Bak. 7: 12, 1901. 
0' Jones, L. R., Vt. R. 13: 299, 1901. 
»* Harding & Stewart, Sc. i^; 314, 1902. 
05 Peglion, v., Zeit. 7; 81. 
0" Smith, E. F., Sc. 19: 416, 1904. 
0' Hegyi, Kizer Kozlem 1: 232, 1899. 

08 Stedman, J. M., Ala. B. 55: 1894. 

09 Prillieux & Delacroix, Rev. Int. d. Vit. D'Oenol, 1894. 

10 Heinz, Cent. f. Bakt. 5: 535, 1889. 

11 Voglino, P., An. R. Ac. d. Agr. d. Torino ^6: 1903. 

12 Hegyi, D., Kiser. Kozlem 2: 1899, No. 5235. 

13 C. R. HO: 678, 1905. 
1* Pethybridge, & Murphy, P. A., Nature (London, 1910), 296, 

No. 2148. 

16 Giddings, N. J., Vt. B. I48: 1910. 

i« Linhart I., Zeit. 10: 116, 1900. 

" Uyeda, Y., Bull. Imp. Centr. Agric. Sta. 1: 39, Dec, 1905. 

18 Uyeda, Y., C. Bak. 13: 327, 1904. 

19 Smith, C. 0., Bot. Gaz. 42: 302, 1906. ■ 

20 Harrison, F. C., C. Bak. 13: 46, 1904. 

21 Harrison, F. C., Sc. 16: 152, 1902. 

22 Harrison, F. C, Ont. B. 137: 1904. 

23 van Hall, C. J. J. Zeit. 13: 129, 1903. 
2^ Uyeda, Y., Bot. Cent. 17: 383, 1907. 
25 Voglino, P., Bot. Cent. 274, 1893. 
29 C. Bak. 5: 33, 1899. 

27 Appel, 0. Arb. aus. Biol. Abt. Kaisel Gesundtheilamt 3: 364, 1903. 

28 Smith, E. F., Sc. 31: 748, 1910. 

29 Brizi, U., Atte. Cong. Nat. Ital. Milan, 1907. 
'0 Smith, R. G., Proc. Lin. Soc. N. S. Wales 29: 449. 

31 Halsted, B. D., N. J. R. 12. 

32 Halsted, B. D., N. J. R. J^: 267, 1891. 

33 Halsted, B. D., Miss. B. 19: 1892. 

34 Burrill, T. J., Proc. 11th Ann. Meeting Soc. Prom. Agr. Sci. 21, 1890. 

35 Ibid. 29, 1891. 

36 Smith, E. F., V. P. P. 12: 109, 1896. 

37 Smith, E. F., Proc. A. A. A. S. 191, 1895. 

38 Stevens, F. L., Press Bull. N. C. 11: Aug. 1903. 



BIBLIOGRAPHY OF INTRODUCTION 57 

"9 Stevens, F. L. and Sackett, W. G., N. C. B. 188: 1903. 
i« Smith, E. F., B. P. I. 141, Pt. II, 1909. 
'" Delacroix, G., C. R. 133: 417, 1030, 1901. 
1^2 Kramer, E., Oest. land. Cent. 1: 11, 1891. 
1" Harrison, C. Bak. 17: 34, 1907. 
'^^ Burrill, T. J., Proc. Am. Soc. Mic. 1888. 
i« Kellerman, W. A. and Swingle, Kan. R. 1: 1888. 
i^" Aderhold and Ruhland, Arb. d. Kais. Biol. Anst f. Land. u. Forst. 
5: 1907. 

1" van Hall, C. J. J. C. Bak. 9: 642. 

i« Delacroix, C. R. 37: 871, 1903. 

i« Smith, E. F., Bot. Gaz. 18: 339, 1893. '' 

15" Smith, E. F., C. Bak. 1: 364, 1895. 

1^' Macchiati, L., Rev. inter d. Vit. et D'Oenol. 1: 129, 1894. 

152 van Hall, C. J. J. C. Bak. 9: 642, 1902. 

153 Burrill, T. J., Billings, the corn stalk disease in cattle investigation 
3: 163, 1889. 

15" Burrill, T. J., 111. B. 6: 1889. 

1" Sta. Sperim Agr. Itat. 30: 482, 1897, also Zeit. 8: 37. 

156 Stone, G. E., and Smith, R. E., R. Mass. (Hatch) 12: 57, 1900. 

1" Stone, G. E., and Monahan, N. F., R. Mass. Sta. 19: 164, 1907. 

158 Galloway, B. T., J. Myc. 6: 114. 

159 Stewart, F. C., N. Y. (Geneva) B. 164, 1889. 
i"" Halsted, B. D., N. J. R. 11: 1890. 

"1 Stone, G. E., and Monahan, N. F., R. Mass. Sta. 19: 161, 1907. 

i«- Rathay, E., Sitz, K. A. K. Wiss. Wien 597, 1899. 

i«3 Jones, L. R., Vt. R. 6: 1892. 

1" Fawcett, H. S., Fla. R. 1908, 80. 

105 Detmers, 0., B. 4: 1891. 

196 Voligno, P., Zeit. 11: 150. 

1" Stone & Smith, Mass. R. 1896. 

188 Smith, R. E., Mass. R. 9: 59, 1897. 

189 Cavara, Sta. Spm. Agr. ital. 30: 482, 1897. 
1'" Peglion, Zeit. 7: 81, 1897. 

1" Halsted, B. D., N. J. R. 430, 1893. 

1" Spieckermann, Land. Jahr. 31: 155, 1902. 

1" Prillieux, B. Soc. Bot. d. France 33: 600, 1896. 

"■• Earle, F. S., Ala. B. 108: 19, 1896. 

1" Prillieux, E. & Delacroix, G., C. R. 118: 668, 1894. 

1" Cavara, B. Soc. Bot. Ital. 241, 1898. 

1" Tubeuf, Nat. Zeit. Forst und Land. 9: 25, 1911. 



58 THE FUNGI WHICH CAUSE PLANT DISEASE 

"8 Jour. Bd. Agr. London, 17: 478. 
"9 Noack, F., Zeit. 3: 191, 1893. 
i8"Lindau, Zeit. J^: I, 1894. 

181 Halsted, B. D., N. J. R. 11: 351, 1890. 

182 Woods, A. F., Sc. 18: 537, 1903. 

183 Rorer, J. B., Proc. Agr. Soc. Trinidad and Tol^ago, 10: No. 4. 
18^ Honing, J. A., Med. Deli. Medan 5: 24. 

185 Comes, O. Atti. d. R. Inst. d'Incor. d. Napolo, 4; 6, 1893. 

186 Potter, Card. Chron. Mch. 6, 145, 1909. 

187 Schwartz, E. J., Ann. Bot. 25: 791, 1911. 

188 Nemec B., Ber. d. deut. Bot. Gez. 29: 48, 1911. 

189 Johnston, J. R,, Phytop. /.- 97, 1911. 

ISO Pavarino, G. L., Atti R. Acad. Lincei CI. Sci. Fis. Mat. e. Nat. 
5.- 355, 1911. 

1" Boyer & Lambert, C. R. 128: 342, 1893. 

i92Pavarino, L., Riv. d. Pat. Veg. 5: 65, 1911. 

193 Halsted, B. D., N. J. B. Q., also R. 1891, 558. 

19^ Cavara, B. Soc. Bot. Ital. 241, 1898. 

196 Stevens, F. L., N. C. R. 31: 74, 1908. 

i96Hori, S., C. Bak. 31: 85, 1911. 

i97Hori, S., B. Imp. Cent. Ag. Ex. Sta. Nishigahara, 1910. 

i^^Idem., 11, 1911. 

199 Marchand, E. F. L., C. R., heb. d. scans, d. I'ac. d. Sc. 150: 1348. 

200 Stewart, F. C, N. Y. (Geneva) R. U: 525, 1895. 

201 Kirk, N. Zeal. R. 13: 427. 

202 Jones, L. R., Vt. B. 66: 1898. 

203 Halsted, B. D., N. J. R. 306, 1896. 

204 McCulloch, L., B. P. I. 225: 1911. 

205 Orton, W. A., Farm B. 41: 309, 1907. 

206 Uyeda, Y., C. Bak. 17: 383, see also extensive Japanese publica- 
tion later by Uyeda. 

20'Sackett W. G., Col. B. 177: 1911. 

208 Bull. No. 2, 1896, p. 76, Torr. Bot. CI. 

209 Jour. Am. Pub. H. Assn., Jan. 1898: 60; Recommendation for the 
study of Bacteria. See also Rept. Soc. Am. Bact. Meeting of 1907. 

210 Pavarino, L., Rend. d. r. Ac. d. Lincei, Classe Scienze, 20: 161, 1911. 



DIVISION III 



EUMYCETES. TRUE FUNGI (p. 3) 



1-17. 19. 22. 23. 29. 45-63 



The Vegetative Body is devoid of chlorophyll and typically 
consists of a more or less branched filament of apical growth, the 
mycelium. This mycelium may be cut into cells by partitions 
(septa) or may be continuous, i. e., without septa. The cells of 
the septate mycelium do not differ essentially from typical plant 
cells except in the absence of chlorophyll. They consist of masses 
of protoplasm, the protoplasts, bearing vacuoles and are more or 

less rich in oils, acids, 

gums, alkaloids, sug- 
ars, resins, coloring 
matter, etc., varying 
in amount and kind 
with the particular 
species and condition 
of the fungus. The 
protoplast is covered 
by a cell wall which 
consists of cellulose 
though often of a 
special quality known 
as fungous cellulose. 
The protoplast bears 
one or in some fungi 
two or more nuclei. 
The vacuolation of the protoplasm, the mode of branching of the 
cells, their color, dimensions, etc., are in some cases quite charac- 
teristic. 

In one class, the Phycomycetes, the active vegetative mycelium 
possesses no septa except such as serve to cut off the sexual or 
other reproductive organs or such as are found in senility. The 

59 




Fig. 35.- 



-Showing a septate mycelium within host 
cells. After Stevens and Hall. 



60 THE FUNGI WHICH CAUSE PLANT DISEASE 

protoplasm is therefore continuous throughout the whole plant 
body and may be regarded as constituting one cell though it may 
be of great extent and bear very numerous nuclei. Such multi- 
nucleate cells, coenocytes, may be regarded as cell complexes with 
the walls omitted. 

In one comparatively small order, the Chytridiales, there is 
often no filamentous mycelium and the vegetative body consists 
merely of a globular, irregularly spherical or amoeboid cell. Such 
forms are thought by some mycologists to be degenerate, to have 
in remote time possessed a mycelium which has been lost owing to 
the present simple mode of life of the fungus, the needs of which 
no longer call for a filamentous body, while others ^ find here 
primitive forms of Phycomycetes, and trace their phylogenetic 
connection with the higher orders of the class. 
Reproduction. 

Vegetative. Most mycelia, if cut in bits and placed in suitable 
environment, continue to grow, soon equaling the parent mycelium 
in size if abundant nourishment obtains. Bits 
of diseased tissue, bearing mycelium, thus con- 
stitute ready means of multiplication and dis- 
persal. 

Asexual Spores. A spore is a special cell set 
aside to reproduce the plant. An asexual spore 
is a spore not produced by a sexual process. 
Manifold forms of asexual spores exist among 
the fungi. In some of the simplest cases, bud- 
like out-growths (gemmae) appear on the myce- 
lium; or portions of the mycelium itself are cut 
off by partitions and the protoplasm inside 
gathers into a mass and protects itself by a 
firmer wall than that of the mycelium, chla- 
mydospores. In other cases special branches, 
Fig. 36.— One form hyphas, are Set apart for the purpose of bearing 
Oidium. After spores. If the spores are cut off from the tip of 
Biolotti. ^j^g branch they are known as conidia or conidio- 

spores, and the branch bearing them is a conidiophore. Conidia 
may be borne singly or in false clusters caused by the youngest 
pushing the older conidia aside; frequently they are produced in 




THE FUxXGI WHICH CAUSE PLANT DISEASE 61 

chains, catenulate, Fig. 36, owing to tiie development of one spore 
below another before the elder spore is shed. Conidia may be 
either simple, composed of one cell, or compound, composed of two 
or more cells. In compound spores each cell is at least potentially 
a spore and can germinate under favorable conditions and per- 
petuate the species. In many compound spores the germinating 
function is sacrificed by one or more of their component cells. 

Conidiophores may consist of loosely branching, rather long 
hyphse, or they may be short, innate, and in close clusters forming 
distinct spore bearing 
spots. Fig. 371. Such 
sporiferous spots when 
naked are called acer- 
vuli. Often the conid- 
iophores are roofed over 
with a net-work of 
woven fungous threads 
thus constituting a 
special spore-bearing 
structure, the pycnidium. 
Figs. 37, 335. Conidio- 
phores may be solitary 
or grow together in bun- 
dles or branch loosely as 
in Fig. 383. 

The basidium, Fig. 38, 
is a special kind of sporo- 

phore bearing at its Fig. 37. — Conidia borne in a pycnidium. After 
„ p Quaintance and Shear. 

apex usually tour, or 

two, small projections, sterigmata, each of which produces one 

spore, for distinction called a basidiospore. 

Some fungi bear the spores loose inside of the swollen tips of 
sporophores as in Fig. 68. The spore bearing structure is then 
called a sporangium and its stalk a sporangiophore. The ascus 
is another spore bearing structure. In it the spores are borne very 
much as they are in the sporangium but usually of definite num- 
ber, 1, 2, 4, 8, 16, etc., eight being the most common number. 
Asci may be naked or covered, scattered or collected in groups. 




62 



THE FUNGI WHICH CAUSE PLANT DISEASE 




When covered, the chamber in which they are borne is called a 
perithecium, Fig. 39; when on an open disk the disk is called an 
apothecium, Fig. 101. 

According to their length of life spores are classed as: 1. rest- 
ing spores whose function is to tide over unfavorable conditions, 

^ hence the common name 
^^^^f^ "winter spore," and 

in contradistinction: 2. 
"Summer spores" which 
are produced in abun- 
dance in warm weather, 
germinate immediately, 
and can ordinarily live 
but a short time. 

In some species the 
spores that are to func- 
tion in water possess cilia, 
and the power of motion. 
These are zoospores or 
swarm spores, Fig. 44. 
At sporing time many kinds of fungi produce special structures 
for the bearing of spores. The fungous threads interweave to 
form a firm, or even a densely solid, mass and constitute a false 
parenchyma. Such are the stalks and caps of the mushrooms and 
of the shelving toadstools, the skin of the puff ball, etc. A cross 
section of such a structure appears much as a true parenchyma, a 
longitudinal section shows it to be merely a mass of interwoven 
fungous threads. 

Sexual Spores are formed by the union of sexual elements, 
gametes. They are most conspicuous among the Oomycetes 
where the antheridium carries the sperms into the oogonium, 
fertilizes the obsphere and produces an oospore. Figs. 53-55. 

As a rule the sexual spores are produced toward the end of the 
vegetative period of the fungus. The asexual spores are produced 
earlier and for a longer period. Sexual spores are commonly 
resting spores. 

Germination of spores. Under suitable environment mature 
spores germinate and eventually give rise to vegetative bodies 



Fig. 38.— Basidia of various ages. After Schenck. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



63 



similar to that of the parent. The most usual mode is for the 
mycelium to rise directly from the spore. In other instances the 
spores produce zoospores which migrate, come to rest, then develop 
a mycelium. In still other cases a short mycelium, promycelium, 
is formed and from this small conidia, sporidia, are made. 
Figs, 217, 240. These conidia give direct rise to the mycelium. 
Spores of some species may by gemmation lead a more or less 
prolonged existence without return to the mycelial stage. 

Heat and Moisture Relation. Like all living things these 
organisms cannot develop without heat and moisture. The 
necessary degree of each varies with different species. Some 



ascospore 



germinafion 




Fig. 39. — A porithecium with asci. After Reddick. 

species are strictly aquatic, and must be surrounded with water; 
others can grow in comparatively dry situations. Generally 
speaking, however, dampness favors fungous development, and 
the growth of most fungi is more vigorous in a damp atmosphere 
than in a drier one. Similarly moderate warmth, as that of summer 
heat, favors fungous growth. Humidity and warmth combined 
are proverbial as producers of mold and mildew. So conspicuous 
is the coincidence of these conditions with fungous growth, that 
in the minds of many a warm damp air is the cause rather than the 
condition of fungous development. 

Respiration with the fungi as with other plants and animals 
consists in oxidation, involving intake and consumption of oxygen 
accompanied by the giving off of carbon dioxide and water, and 



64 THE FUNGI WHICH CAUSE PLANT DISEASE 

since no photosynthesis occurs, this process is never masked as it 
is in the case of the chlorophyll-bearing plants. 

In nutrition requirements there is great diversity; but in all 
cases carbon must be taken from some organic source. Starch, 
sugar, cellulose and kindred compounds are frequent sources of 
the carbon food supply. Nitrogenous foods are, generally speaking, 
not required in such abundance by the Eumycetes as by the 
bacteria and advantage may frequently be taken of this fact in 
isolating the fungi from bacteria by growing them on media poor 
in nitrogen, in which case the fungi often outgrow the bacteria. 

The color of the fungi is determined largely by the constitution 
of the media upon which they grow.-' ^' "*' ^ 

Many fungi exhibit a peculiar heteroecism, that is, part of their 
life cycle is passed through upon one host, part of it upon another 
host, even of very distant botanical kinship. Thus among the 
rusts; in one instance part of the life cycle is upon the apple, the 
remainder upon the cedar tree. Fungi also exhibit polymor- 
phism, i. e., in one stage they exhibit one spore form and in an- 
other stage another spore form totally different. In this way 
several apparently quite distinct types of spores and sporiferous 
structures may belong to the same species. 

Classification of Fungi.®' ''' ^^' "' ^^' ^^ The true fungi in them- 
selves constitute a very large group made up of diverse forms, many 
of which are as yet little known. Any satisfactory system of classi- 
fication is impossible until much more knowledge is gotten regard- 
ing their morphology, cytology, life histories and especially their re- 
lations to their hosts. According to present knowledge they com- 
prise very numerous species distributed in three classes as follows : 

Key to Classes of Eumycetes 
Mycelium continuous in vegetative 

stage Class 1 . Phy corny cetes, p. 65. 

Mycelium septate 

Spores in asci Class 2. Ascomycetes, p. 113. 

Spores on basidia* Class 3. Basidiomycetes, p. 298. 

Not as above; spores on conidio- 
phores, naked, or in pycnidia; 

or spores quite unknown Fungi Imperfecti, p. 475. 

* In the rusts and smuts the promyceUum is regarded as a basidium. 



THE FUNGI WHICH CAUSE PLANT DISEASE 65 

Class I. Phycomycetes, Alga-like Fungi (p. 64) 

The Phycomycetes are characterized by the absence of septa in 
the mycelium except in sporing branches, where they occur to 
cut off the spore-bearing cells or the gametangia, and in old fila- 
ments. The body is multi-nucleate and sexual spores as well as 
asexual ones are usually, though not always, produced. Some of 
the Phycomycetes live in water and possess zoospores, others are 
parasitic on land plants and bear conidia or sporangia. These 
may germinate either by germ tubes or by zoospores. The char- 
acteristic fertilization consists of a union of two gametes which 
may be like in character (isogamy) or unlike (heterogamy). If 
the sexual organs are unlike the receptacle which bears the sexual 
spores is called the oogonium, its eggs before fertilization oospheres, 
and the spores oospores. The receptacle bearing the fertiliz- 
ing gamete is the antheridium, and the fertilizing elements 
are the sperms. The sperms may be motile and swim or creep 
into the oogonium or the antheridium may develop a tube leading 
into the oogonium through which the fertilizing nuclei pass. In 
some forms which, by their sexual or asexual spores, show relation 
to the Phycomycetes the mycelium is wanting and the vegetative 
body is reduced to a single spherical or amoeboid cell, which fre- 
quently lives in a purely parasitic manner entirely imbedded in 
the protoplasts of its host. This mode of life constitutes the 
strictest kind of parasitism inasmuch as the fungus derives its 
nourishment from the still living host cell. 

Key to Orders of Phycomycetes 

Sexual spores when present heteroga- 

mous Subclass I. Obmycetes, p. 66. 

Conidia absent; sexual spores and zoo- 
sporangia only 
Mycelium poorly developed, frequently 
reduced to a single cell 
Fruiting mycelium a single cell, or a 
group of cells in a sorus, forming 
either asexual resting spores or 
sporangia from the entire proto- 
plasmic mass 1. Chytridiales, p. 66. 



66 THE FUNGI WHICH CAUSE PLAxNT DISEASE 

Fruiting mycelium multicellular, 
some cells forming sporangia, 
others producing gametes and 

oospores 2. Ancylistidiales. 

Mycelium well developed 
Fertilization by motile sperms. ... 3. Monoblepharidiales. 
Fertilization through an anther- 

idial tube 4. Saprolegniales, p. 74. 

Conidia present 5. Peronosporales, p. 77. 

Sexual spores isogamous, formed by the 

union of similar gametes . .Subclass II. Zygomycetes, p. 101. 
Asexual spores several, in sporangia ... 6. Mucorales, p. 102. 
Asexual spores solitary, conidia 7. Entomophthorales,p. 107. 

Of these orders the Ancylistidiales which are parasitic upon 
Algae, and the Monoblepharidiales which are saprophytic will not 
be considered further. 

Subclass Oomycetes (p. 65) 

In the Oomycetes there is pronounced difference between the 
male and female sexual organs. The oogonium is comparatively 
large, and contains one or more large passive eggs (oospheres), 
which are fertilized by sperms, differentiated or not, which either 
swim to the oogonium by cilia, creep to it, or are carried to it by 
a fertilizing tube. Oospores are in some species produced fre- 
quently and abundantly while in others they are entirely unknown. 
The asexual reproduction is by either conidia or sporangia. 

Chytridiales (p. 65) 

The members of this order are the simplest of any of the Phy- 
comycetes. Many of them are single, more or less globose, undif- 
ferentiated cells, others have a more or less prominent haustoria- 
like mycelium, while but few have any approach to a true myce- 
lial development. Most are intracellular parasites; a few of the 
more highly developed genera are intercellular parasites. With 
few exceptions reproduction is entirely asexual, all spores being 
formed directly from the vegetative cell. Zoosporangia and thick- 



THE FUNGI WHICH CAUSE PLANT DISEASE 67 

walled resting spores are produced. The zoospores have either 
one or two cilia. There are over forty genera and two hundred 
species. The majority of the species are inconspicuous parasites 
of algse and infusoria; but some genera, like Synchytrium and 
Urophlyctis, produce conspicuous sori and even cause hyper- 
trophy of land plants. 

Key to Families of Chytridiales 

Spores all asexual, or rarely formed by the 
union of free-swimming gametes 
Mycelium none 

Sporangia solitary 1. Olpidiaceae, jx 67. 

Sporangia grouped into sori 2. Synchytriaceae, \). 69. 

Mycelium present 

Mycelium of delicate, evanescent haus- 
toria-like strands 
Mycelium limited, sporangia ter- 
minal 3. Rhizidiaceae. 

Mycelium extended, sporangia ter- 
minal or intercalary 4. Cladochytriaceae, p. 72. 

Mycelium of permanent hyphse 5. Hypochytriaceae. 

Spores both sexual and asexual 

Gametes hetrogamous 6. Oochytriaceae, p. 73. 

Gametes isogamous 7. Zygochytriaceae. 

Four only of these families have parasitic representatives on 
higher plants in America, the others being chiefly parasitic on 
algae and infusoria. 

Olpidiaceae 

This family which contains the simplest members of the order 
has no mycelium; the entire plant body consists of a single more 
or less globular or elliptic cell which never divides, but at maturity 
forms either a zoosporangium or an asexual resting spore which 
after a period of rest gives rise to swarm spores. All the species 
are endobiotic. The family contains some forty species but few 
of which are of economic importance. 



68 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Key to Genera of Olpidiaceae 



Vegetative body amoeboid 

Vegetative body of definite form 
Sporangia free in the cells of the host 
Sporangial membrane very delicate, 

evanescent 

Sporangial membrane firm, swarm 
spores escaping by a definite open- 
ing 
Sporangium globular or eUipsoid 
Sporangium with only one or two 
openings 
Swarm spores uniciliate 
Vegetative cells globose or sub- 
globose 
Vegetative cells stellate 
Swarm spores biciliate 
Sporangium with several openings 

Sporangium elongate 

Sporangial membrane vmited to the wall of 
the host cell 



1. Reessia. 



2. Sphaerita. 



3. Olpidium, p. 68. 

4. Asterocystis, p. 69. 

5. Olpidiopsis. 

6. Pleotrachelus. 

7. Ectrogella. 

8. Pleolpidium. 



Olpidium A Braun 

In this genus a single swarm spore invades the cell of the host 

and develops in its pro- 
toplasm. Later a cell 
wall forms and the vege- 
tative body changes into 
a zoosporangium which 
develops a neck. This 
reaches to the outside 
of the host even though 
the fungus be developed 
several cells below the 
surface. The uniciliate 
zoospores pass out 
through this neck to 
Thick-walled resting spores are also formed. 




Fig. 40. — O. brassicoe; right, three sporangia in 
a cell; left, resting spores. After Woronin. 



make their escape. 



THE FUNGI WHICH CAUSE PLANT DISEASE 69 

There are some twenty-five species most of which five as para- 
sites on alga?, worms, pollen grains, etc. 

O. brassicae (Wor.) Dang.^ is parasitic on quite young cabbage 
seedlings, sometimes infecting cells deeply seated in the host. 
The same or a nearly related species also attacks tobacco and 
several weeds. 

Sporangia solitary or several in each infected host cell, globular ; 
zoospores numerous, globose, uniciliate; resting spores globose, 
with a wrinkled epispore which gives them more or less of a star- 
like appearance. Fig. 40. 

Asterocystis de Wildeman (p. 68) 

There is a single species, A. radicis d. Wild.^ which differs from 
Olpidium in its stellate vegetative cell and the absence of the tube 
for the escape of the zoospores, this being accomplished by the 
breaking away of the tissues of the host. The fungus attacks the 
roots of various plants, notably flax, Brassica and other crucifers, 
Plantago, Veronica and numerous grasses, producing chlorosis. 
It has not been reported from America. 

A Chytridiaceous fungus of unknown genus thought to stand 
near the Olpidiacese and Synchytriacese has been described by 
Home ^ as the cause of an Irish potato disease. 

Synchytriaceae (p. 67) 

The infecting zoospore invades the host cell and becomes 
parasitic upon the still living protoplasm. Hypertrophy of this and 
adjacent host cells is usually induced, resulting in the formation of 
a small gall around the infected cell. This gall is often colored 
and bears a superficial resemblance to a rust sorus. The parasite 
enlarges until it occupies nearly the whole of the host cell. In 
Synchytrium the one nucleus then enlarges and divides to produce 
very numerous nuclei. ^' ^°' ^^' ^- The whole mass then divides 
into segments regarded as sporangia, and each sporangium divides 
into numerous uninucleate parts, each of which develops into a 
zoospore. In some species development is arrested before the 
division of the primary nucleus and the protoplast becomes 
spherical, invests itself with a thick wall and becomes a resting 



70 



THE FUNGI WHICH CAUSE PLANT DISEASE 



spore. (Fig. 42.) After a more or less protracted period of rest 
this produces zoospores. 

The family includes some fifty species, all of which, except two 
small genera, are parasitic upon land plants. 

Key to Genera of Synchytriaceae 

Zoosporangia formed by direct division of 

the entire plasma of the young fruiting 

body. 

Swarm sporangia completely filling the 

host cell, membrane united to the 

wall of the host cell 1. Rozella. 

Swarm sporangia lying free in the host cell 

Parasitic on algae 2. Woronina. 

Parasitic on land plants 3. Woroniella. 

Zoosporangia formed by division of an ini- 
tial cell to forma sorus of sporangial cells. 
Sporangia formed directly from the full- 
grown plant body 4. Synchytrium, p. 70. 

Sporangia formed by the division of a thin- 
walled mother cell after its escape 
from the plant body 5. Pycnochytrium, p. 72. 

Synchytrium de Bary & Woronin 
Upon reaching maturity the plant body develops directly into 
a sporangial sorus. Both zoosporangia and winter spores present. 





I'lG. 41. — Showing nucleus in Synchytrium. After Stevens. 

S. endobioticum (Schilb.) Perc, the cause of a very serious wart 
disease of the potato, was originally described as Chrysophlyctis 
endobioticum by Schilberszky ^^ and transferred to Synchytrium 
by Percival.^^ It invaded America about 1909.^^^ It was reported 
from Africa by Zimmermann.^^ 



THE FUNGI WHICH CAUSE PLANT DISEASE 



71 




A B 

Fig. 42. — A, section showing sporangia or 
sporocysts; B, zoospores, ciliated and 
amoeboid. After Percival. 



In summer the resting spores which average about 52 fi in diam- 
eter are found in abundance in the host cells near the surface, few 

in the outer layer, more below 
down to the sixth or eighth 
row of cells. Each resting 
spore contains several hun- 
dred roundish zoospores which 
measure 2-2.5 ^i. In spring 
the resting spores germinate, 
freeing numerous pear-shaped 
uniciliate zoospores, which at 
first swim with a jerky motion 
but soon become amoeboid. 
The summer sporangia may 
germinate without protracted 
rest, and also give rise to zoospores. Another type of sporangium 
consists of thin sacs, produced singly or two to five in a sorus, 
each bearing numerous zoospores somewhat smaller than those 
from the first type of sporangia. 

The zoospores, says Percival, enter the potato apparently in 
the amoeboid state in bud tissue of rhizomes and in the "eyes" of 
young tubers. Usually only one zoospore enters each cell but 
occasionally more may do so. Crushed sporangia produced 
characteristic warts in three to four days when placed on suscep- 
tible parts. Successful inoculations were also made by Salmon and 
Crompton.^® The cytology has been studied by Percival. ^^ The 
full grown tumors vary in size from that of a 
pea to a hen's egg, and represent metamor- 
phosed branch systems. 

S. vaccinii Thomas ^^"^^ is the cause of a 
disease of the cranberry and related hosts. It 
forms numerous, small, reddish galls in which, 
deeply embedded, are the sori. 

S. papillatum Farl."° occurs on Alfilaria in 
California. 

Other species of Synchytrium are found upon 
dandelion, ffinothera, Geranium, Amphicarpa, Ornithogalum, clo- 
ver, elm, etc., but as yet are not of economic importance in America. 




Fig. 43.— GaU of S. 
vaccinii. After 
Shear. 



72 THE FUNGI WHICH CAUSE PLANT DISEASE 



Pycnochytrium Schroter (p. 70) 

Only resting spores are known. In germination their proto- 
plasmic contents emerges and forms a sporangial sorus. 

P. anemones (D. C.) Schr. is common on various species of 
Anemone; P. globosum (Schr.) Schr. on the violet, blackberry, 
maple, etc. None of the species are of any considerable economic 
importance. 

Cladochytriaceae (p. 67) 

A branching mycelium runs through or between the cells of 
the host drawing nourishment from many cells. Sporangia are 
either apical or intercalary and contain uniciliate zoospores. 
Resting spores are also produced. There are about a half dozen 
genera and some thirty species. 



Key to Genera of Cladochytriaceae 

Resting spores only known 1. Physoderma. 

Swarm spores only known 
Intracellular and endo])hytic 

Swarm spores at first ciliate, becoming 

amoeboid 2. Cladochytrium, p. 72. 

Swarm spores not becoming amoeboid 3. Pyroctonium, p. 73. 
Living free among the hosts 

Sporangia opening by a pore 4. Amcebochytrium. 

Sporangia opening by a lid 5. Nowakowskiella. 



Cladochytrium Nowakowski-^ 

The genus contains about ten species of intercellular parasites 
with branched mycelial threads. The zoosporangium is globose, 
and opens by a distinct mouth which develops a tube for the 
escape of the zoospores much as does Olpidium. Resting spores 
are not known. 



THE FUNGI WHICH CAUSE PLANT DISEASE 73 

The most important species are C. tenue Nowak. on Acorus 
and Iris; C. graminis Busg. on various grasses, C. violae Berlese 
on violets.-" 

C. viticulum Pru.^ and C. mori Pru.^^ have been described on 
grape and mulberry _, but further study is very desirable. 

C. brassicae E. & B.'-"" is described from dead leaves of cab- 
bage. 

C. csespitis G. & M.-^ occurs in France on Lolium. 

Pyroctonium sphaericum Pru.-^ was reported in 1894 as the 
cause of wheat disease in France but has not since been 
found. 



Odchytriaceae (p. 67) 

The plant body is either an undifferentiated cell or a well de- 
veloped mycelium; reproduction by means of asexual swarm 
spores and sexual resting spores. Of the three genera only one 
is of economic importance. 



Key to Genera of Oochytriaceae 

Mycelium entirely lacking 1. Diplophysa. 

Mycelium present 

Mycelium producing a single gametan- 

gium 2. Polyphagus. 

Mycelium producing several gametangia 3. Urophlyctis, p. 73. 



Urophlyctis Schroter 

Mycelium endophytic, producing zoosporangia on the surface 
of the host and thick- walled oospores within the tissues; zoospores 
uniciliate. The genus contains some half dozen species all of 
which are parasitic on higher plants. 

U. leperoides (Sacc. & Trab.) Magnus -^' -^ causes "beet root 
tumor," in North Africa and Western Europe. The rootlets of 
the upper portion of the root are attacked and develop tumorous 
growths, sometimes as large as a walnut. The infection is super- 



74 



THE FUNGI WHICH CAUSE PLANT DISEASE 



ficial and does not extend to the fleshy tap root. The develop- 
ment of the spores is the typical method for the genus, the an- 
theridium persisting at the base of the oogonium and retaining its 
hyphal connection, while the oogonium becomes free just before 

conjugation. The oospores are 
subglobose, depressed on one side, 
smooth, brown, 45-50 x 30 /i. 

U. pulposa (Wallr.) Schr., a 
closely related species occurs on 
the aerial portions of Chenopo- 
dium and Atriplex. 

U. alfalfse Mag.^"' '^'^ ''^' '''' ^^^ 
causes a crown gall of alfalfa in 
America and Europe. The dis- 
ease is quite similar to that de- 




FiG. 44.— Urophlyctis pulposa. a, zoo- scribed abovc for the beet. 

sporangium; h, zoospores; c, oospore 
formation ; d, mature oospores. After 
Schroter. 



U. trifolii (Pass.), Mag., a 
closely related species, forms 
small, glassy, globose pustules on the leaves and petioles of 
various species of clover in Europe. 

U. hemispherica (Speg.) Syd.^^ in South America, U. krieger- 
iana Mag.^^ in Europe and U. pluriannulata (B. & C.) Farl.^'^ 
in America form Synchytrium-like galls on various umbelliferous 
genera. All may belong to the same species. U. major Schr. and 
U. rubsaameri Mag. infect respectively the leaves and the roots of 
Rumex. 



Saprolegniales (p. 66) 

Asexual reproduction is mainly by biciliated spores formed in 
large numbers in sporangia of various shapes. Sexual spores, 
often apogamous, are produced in most genera, much after the 
fashion of those of the Peronosporales except that more than one 
oospore is frequently formed in one oogonium. ^^^ 

The order consists of fifty or more species, mostly parasites 
or saprophytes upon aquatic organisms. One species of the genus 
Achlya causes serious disease in young fish. 

There are three families: 



THE FUNGI WHICH CAUSE PLANT DISEASE 75 



Key to Families of Saprolegniales 

Vegetative mycelium of tiiick tubular hy- 
phse; aquatic; zoosporangia cylindrical 
not much thicker than the mycelium 

Filaments uniform, not constricted 1. Saprolegniaceae. 

Filaments constricted regularly 2. Leptomitaceae. 

Vegetative mycelium of thin hyphse, mostly 
parasitic or saprophytic on plant tis- 
sues; zoosporangia much broader than 
the mycelium, mostly globular 3. Pythiaceae, p. 75. 

Dictyuchus Leitgeb. 

This genus of the Saprolegniaceae contains the only parasite 
genus in the first two families. 

Sporangia cylindric or clavate, swarm-spores becoming walled 
within the sporangium and emerging singly through its lateral 
walls. The genus is usually saprophytic but, D. monosporus 
Leit. is said by Halsted to be a serious hyacinth enemy. ^^^ 

The other members are mainly on dead or diseased insects or 
other animals that are in water or are on diseased algse or in water- 
slime. 

Pythiaceae ^^^ 

This family shows affinity with both the Peronosporales and 
the Saprolegniales and is sometimes classed with the one, some- 
times with the other. It consists of three genera and about twenty 
species characterized by a mycelium of very delicate hyphse which 
show no differentiation into sterile and fertile regions. The 
species are either aquatic or terrestial; in the latter case they are 
soil fungi that grow to maturity upon seedlings. When of aerial 
habit the sporangia become conidial in character, that is, they are 
detached from the hypha before the discharge of the zoospores. 

Zoosporangia elongate 1. Nematosporangium. 

Zoosporangia spherical or oval, not linear 
Zoospores formed outside of the zoospo- 
rangia 2. Pythium, p. 76. 

Zoospores formed within the zoospo- 
rangia 3. Pythiacystis, p. 77. 



76 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Pythium Pringsheim ^^ (p. 75) 

The mycelium is found in abundance in and about the infected 
tissue as fine, branched continuous threads. These, in the terrestial 




Fig. 45. — Cucumber seedlings. Pots 5, 6, and 8 inoculated with Pythium. Pot 7, 
Control. After Atkinson. 

species, bear conidia on branches which are of the same character 
as the mycelium itself. The conidia germinate either by a rupture 

of the wall or by the formation of a 
beak-like process through which the 
protoplasm is extruded, after which it 
becomes differentiated into zoospores. 
Gemmae, very like the conidia in ap- 
pearance, are also produced. 

The oogonia are quite like the conidia 
and gemmae in structure but develop 
oospores within. The oogonium is at 
first multinucleate but as the oosphere 
matures all of the nuclei except one 
migrate toward the periphery, the peri- 
plasm, or degenerate in the ooplasm, re- 
sulting at maturity in an uninucleate egg. This is fertilized by 
one nucleus from the antheridium. No sperm is differentiated, 




Fig. 46. — Fertilization ii 

thium, showing oogonium, 
antheridium, oospore, peri- 
plasm and the c? and Q 
nuclei. After Miyaki. 



THE PTINGI WHICH CAUSE PLANT DISEASE 



77 



and the contents of the antheridium are carried over to the egg 
by a fertilizing tube. Members of the 
genus are aggressively parasitic only under 
most favorable environmental conditions 
of heat and moisture. 

Some sixteen species are known. 

P. de baryanum Hesse, is most com- 
j^Qj^ 33-37 g^g ^Y\e cause of "Damping Off." 

Zoosporangia or "conidia" globose to 
elliptic, usually papillate, 20-25 n; gemmaj 
similar in form and size; oospores globose, 
hyaline, smooth, 15-18 fx. 

P. intermedium de Bary, causes a 
"damping off" of fern prothalia,^^ P. 
gracile Schenck, a rot of ginger; ^^ P. 
palmivorum Butler, a palm disease in India. ^''' 




Fig. 47. — P. citriophora; de- 
velopment of swarnispores 
from sporangia. After 
Smith and Smith. 



Pithiacystis, Smith & Smith (p. 75) 

The sporangiophore is delicate; septate; and bears numerous 
sporangia sympodially. These produce many biciliate zoospores 

internally. No oospores have been 
seen. Only one species is known. 
P. citriophora Sm. & Sm.^^' '^ 
Parasitic on lemons, the sterile 
mycelium inhabiting the rind; 
spores normally formed in the soil 
near infected fruits; sporangia ovate 
or lemon-shaped, papillate, 20-60 x 

Fig. 48.— Sporangiophores and spo- Qnqn ,, Qvprnmns- 35 X 50 u borne 
rangia of Pythiacystis. After '^^ ^" ^' ^Veragmg OO X OU /X, uorne 

Smith and Smith. sympodially; zoospores 10-16 n, 

at first elongate, becoming rounded and bearing two lateral cilia. 

This was first noted by Smith and Smith ^^' ^° on rotting lemons 
in California. Infection by pure cultures proved that the fungus 
was the true cause of the rot. 

Peronosporales (p. 66) 

These fungi constitute an order characterized by a richly 
developed, branching, non-septate, usually coarse, mycelium of 





78 THE FUNGI WHICH CAUSE PLANT DISEASE 

strictly parasitic habit. The mycelial threads in most genera 
wander between the host cells and draw nutriment from them by 
short branches, sucking organs (haustoria), (Fig. 49) of various 
forms, which penetrate into the victimized cell. In one genus 
only, Phytophthora, does the mycelium grow directly through cells. 
Two kinds of spores are produced, sexual and asexual. The 
sexual spores result from the union of two 
unlike gametes, the egg (oosphere) and 
sperm, borne respectively in the oogonium 
and antheridium. Each oogonium bears a 
solitary oosphere. Fertilization is accom- 
plished by means of a tube from the anther- 
idium and penetrating into the oogonium. 
The sexual spores are thick walled, re- 

FiG. 49. — Haustoria of a . , . . , • . 

Peronospora. After sistant, and usually require a long time to 
^^ reach maturity. They are, therefore, often 

called "resting spores." In germinating the sexual spores pro- 
duce either germ tubes or develop directly into zoosporangia. 
The asexual spores are conidia. They are borne on conidio- 
phores which arise from the mycelium and which may be short 
or long, simple or branched, subepidermal or superficial accord- 
ing to the habit of the species. The conidia in various genera 
germinate by three methods, (1) a germ tube is sent out by 
the conidium, (2) the entire protoplasmic contents of the spore 
passes outside the spore wall and then forms a germ tube, or 
(3) the conidium by internal division breaks up into zoospores. 

Key to Families of Peronosporales 

Conidiophores, short, thick, subepidermal, 

conidia catenulate 1. Albuginaceae, p. 78. 

Conidiophores, longer, superficial, simple or 

branched, conidia not catenulate 2. Peronosporaceae, p. 82. 

Albuginaceae 

There is a single genus. Albugo (Persoon) Roussell. This genus 
of about fifteen species is entirely parasitic upon flowering plants. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



79 



causing the "white rusts." The conidia are borne in white 
bhster-Uke sori under the raised and finally ruptured epidermis 
of the host. The conidiophores are short, club-shaped, arranged 




Fig. 50. — Albugo. A, section through a sorus showing epidermis, conidia, 
conidiophores and myceUum; B, conidiophores and conidia; C, myce- 
lium and haustoria. After Bergen and Davis. 

in clusters; the spores are borne in basipetal succession and 
remain attached in rather long chains unless disturbed. 

The mycelium is very fine, intercellular and penetrates the cells 
by globular haustoria. The rudimentary oogonium is multi- 
nucleate and filled with uniform proto- 
plasm. As the oogonium grows older 
the protoplasm within differentiates 
into two parts, the inner part of dense 
protoplasm, the oosphere, and the 
outer part less dense, the periplasm. ^^ 
Figs. 51, 53, 54. During this process 
the nuclei enlarge, undergo one or two 
mitoses, Fig. 54, and in some species 
all the nuclei except one pass to the 

periplasm. In other species the Fig. 5 1.— Multiple fertilization 
... . ,,. , , . , •, inA. bliti. Antheridial tube 

oosphere is multmucleate at maturity. discharging sperms. After 

The latter type is fertilized by nu- Stevens. 

merous nuclei from the antheridium, the former by a single nu- 

cleus.^^'^^' ^^ After fertilization the oosphere matures to an 

oospore. 




80 



THE FUNGI WHICH CAUSE PLANT DISEASE 



The globular oospores fall into two classes; '^^ first tuber- 
culate or ridged; second, reticulated. These are illustrated in 
Fig. 52. 













Fig. 52. — Oospores of Albugo. 1. A. oandida. 2. A. tropica. 3. A. ipomoea;- 
panduranse. 4. A. Icpigoni. 5. A. swertiie. 6. A. tragopogonis. 7. A. bliti. 8. A. 
platensis. 9. A. occidentalis. 10. A. portulacse. After Wilson. 

The conidia in germination usually produce several ovate 
zoospores with two unequal, lateral cilia. After a brief period of 
motility they became walled and produced germ tubes capable of 
infecting susceptible hosts. The oospores after a period of rest 



THE FUNGI WHICH CAUSE PLANT DISEASE 



81 



germinate in a similar manner. Conidia germinate freely only if 
they are chilled/" 

A. Candida (Pers.) Roussel/^ Sori on all parts of the host except 
the roots, white or rarely light-yellow, prominent and rather deep- 
seated, variable in size and shape, often confluent and frequently 
producing marked distortion of the host; conidiophores hyaline, 
clavate, about 35-40 x 15-17 m; conidia, globular, hyaline, with 
uniformly thin walls, 15-18 ix; oospores, much less common than 
conidia, usually confined to stems and fruits, chocolate-colored. 





Fig. 53. — A. bliti, young oogo- 
nium and antheridium show- 
ing nuclei. After Stevens. 



Fig. 54.— a. bliti, 
showing differ- 
entiation of 
ooplasm and 
periplasm, the 
nuclei in mito- 
sis. After 
Stevens. 




Fig. 55. — A. bliti, an- 
theridium showing 
the multinucleate 
tube. After Ste- 



40-55 ix; epispore thick, verrucose, or with low blunt ridges 
which are often confluent and irregularly branched. 

This is the most widely distributed and most common species 
of the genus. It occurs throughout the world on a large number 
of cruciferous hosts, and often gives rise to very pronounced 
hypertrophy. Practically all cultivated crucifers, cabbage, 
radish, turnip, etc., are subject to attacks of this fungus. In 
Europe the caper and mignonette are attacked by the same 
species. It has been reported in New York on Tropoeolum.'*^ 

A. ipomoeae-panduranaB (Schw.) Sw.^^' ^^° Sori amphigenous or 
caulicolous, white or light yellow, prominent, superficial, 0.5- 
20 mm., rounded, often confluent and frequently producing 
marked distortions of the host; conidiophores hyaline, clavate. 



82 THE FUNGI WHICH CAUSE PLANT DISEASE 

unequally curved at base, 15 x 30 /x; conidia hyaline; short- 
cylindric, all alike or the terminal more rounded, 14-20 x 12-18 /x; 
the membrane with an equatorial thickening, usually very pro- 
nounced. Oosporic sori separate from the conidial, caulicolous, 
rarely on petioles, 1-2 x 5-6 cm. or even more, causing marked 
distortion; oospores light yellowish-brown, 25-55 (jl; epispore 
papillate or with irregular, curved ridges. 

Common throughout the world on various species of Convol- 
vulaceae, morning glory, moon flower, sweet potato, etc., although 
causing but little damage. 

A. occidentalis G. W. W., reported by Pammel '"^ on the beet 
has been collected but once. 

A. portulaceae (D. C.) Kze. on purslane ^^ and A. bliti (Biv.) 
Kze.^- occur on Amaranthus and related plants. 

A. tragopogonis (D. C.) S. F. G.^^' ^^ Sori hypophyllous or 
caulicolous, prominent, deep-seated, white or yellowish, pul- 
verulent, rounded or elongate, 1-3 x 1-8 mm; conidiophores 
hyaline, clavate, about 12-15 x 40-50 fx; conidia, 12-15 x 18-22 /x; 
light yellow or hyaline, short-cylindric, the terminal larger and 
less angular than the others, membrane with an equatorial thick- 
ening; oospores produced in stems and leaves, dark brown or 
almost black at maturity, opaque, 44-68 /x, epispore reticulate, 
areolae 2 /x; wing bearing papillate tubercles at its angles. 

A cosmopolitan species of less economic importance in America 
than in Europe attacking a wide range of hosts of the Compositse. 
Salsify is the chief economic host. 

Peronosporaceae (p. 78) 

The members of this family, producing the diseases commonly 
known as the "downy mildews," have been long known and much 
studied. They contain many important plant pathogens. The 
globular oospores are in general indistinguishable from those of 
the Aibuginaceae but the conidiophores are quite different from 
those of that family, being aerial instead of subepidemal. In 
most cases they are branching and tree-like, Fig. 63, but in a 
few genera they are short. The oospore in such genera as have 
been studied (Peronospora ^^ Sclerospora ''^) is formed as in Albugo 
resulting when mature in an uninucleate egg surrounded by a 



THE FUNGI WHICH CAUSE PLANT DISEASE 83 

periplasm bearing the degenerate supernumerary nuclei. Fer- 
tilization is as in the Albugos that have an uninucleate 
eea; ^^' ^^' ^^' ^^ 

The family has suffered many revisions of classification and 
much renaming of genera. Plasmopara and Peronospora are 
especially rich in a masquerade of names. ^^' ^^"'^^* 

Key to Genera op Peronosporaceae 

Conidiophores scorpioid-cymosely branched ; 

conidia germinating by zoospores 1. Phytophthora, p. 84. 

Conidiophores simple, monopodially or 

dichotomously branched. 

Conidiophores simple or monopodially 

branched; conidia germinating by 

zoospores or by a plasma 

Conidiophores simple or irregularly 

branched 2. Kawakamia, p. 89. 

Conidiophores regularly branched 
Conidiophores with the main a.xis 
indurate, the lateral branches 

reduced and basidia-like 3. Basidiophora, p. 89. 

Conidiophores with the main 

axis not indurate, the lateral 

branches developed normally. 

Conidiophores fugacious, stout, 

sparingly branched; oospore 

permanently united to the 

wall of the oogonium 4. Sclerospora, p. 89. 

Conidiophores persistent, slender, 
usually freely branched; oo- 
spore free from the wall of 
the oogonium 
Branches of the conidiophore 

apically obtuse 5. Plasmopara, p. 90. 

Branches of the conidiophore 

apically acute 6. Peronoplasmopara,p.93. 

Conidiophores dichotomously branched; 
conidia germinating by a germ tube. 
Conidiophores with subapical disk-like 
enlargements from which the ul- 



84 



THE FUNGI WHICH CAUSE PLANT DISEASE 



timate branchlets arise radially; 
germ tube produced from the apex 

of the conidia 7. Bremia, p. 95. 

Conidiophores without subapical en- 
largements; conidia germinating 
from the side 8. Peronospora, p. 95. 



Phytophthora de Bary (p. 83) 

This genus is of especial interest on account of its one exceed- 
ingly destructive representative, P. infestans, which occupies an 
historic position in phytopathology as one of the earliest of para- 
sitic fungi to receive study in any way complete or adequate; 
study moreover which did much to turn attention and interest 
toward plant pathology. 

A distinctive character is that the conidiophores have irregular 
thickenings below the apparently lateral conidia. The conidio- 
phore is at first simple and bears a single apical conidium, after 
the production of which a lateral branch arises below the conidium 
and grows on in such a way as to give the first conidium a lateral 
appearance. This process is, in some species, repeated until a 
large scorpioid cyme is produced. The genus 
contains seven or eight species, all parasitic. 
The mycelium is much branched, non-septate, 
hyaline; the conidiophores arise singly or in 
groups from the stomata, or break through 
the epidermis; conidia oval, papillate; zoo- 
spores oval, biciliate, escaping by rupture of 
the papilla; oospores, when present, with the 
epispore more or less ridged. 

P. phaseoli Thax.^^"^^ Mycelium well de- 
veloped, intracellular; conidiophores single or 
in clusters from the stomata, simple or 
branched below, apparently simple above 
but really one to many times cymosely 
branched; conidia oval or elliptic, papillate, 35-50 x 20-24 /x; 
germination by about fifteen zoospores. Oogonia in the seed 
coats or cotyledons of seeds, rarely in the pods, thin walled, 
slightly folded; subspherical 23-28 fi; oospores spherical or 




Fig. 56. — Structural de- 
tails of P. phaseoli. 
After Thaxter. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



85 




86 



THE FUNGI WHICH CAUSE PLANT DISEASE 



subspherical with smooth, moderately thick walls, hj^aline or 
light yellow, 18-26 /x. It was described on lima beans in 1889. 
The methods of infection were studied by Sturgis ^'- who showed 
that spores are carried to the basal portion of the style and ovary 
by visiting insects. Oospores were described and extensive arti- 
ficial culture experiments made by Clinton ^^ who first grew the 
fungus successfully in pure culture on corn-meal-agar, and other 
media, on which oospores were produced in abundance. 

The species is unique within the genus on account of the single 
conidia which are borne at the apex of apparently simple conidio- 
phores but subtended by several enlargements of the kind so 
characteristic of the genus. 
P. infestans (Mont.) de Bary.^^' '''- ''''^'^ 

Mycelium well developed, probably perennial; conidiophores 
single or in groups of 2-4 from the stomata; scorpiose-cymosely 
branched; conidia 27-30 x 15-20 fj,, ovoid, germinating by about 
six to sixteen zoospores. 

On diseased solanaceous hosts, particularly the potato and 
tomato,^^ this species is very destructive. It was first described 

in 1845 as a Botrytis and 
has since been the subject 
of many extensive papers. 

The conidiophores are 
abundant on the lower sides 
of infected leaves near the 
invasion line. The myce- 
lium migrates between the 
cells piercing them with 
haustoria. 

The existence of oospores 
is a much controverted 
point; the structures re- 
ported by Smith ^''"^'' as oospores probably belonged to some other 
fungus. Recently Jones ^^ found peculiar thick-walled bodies, 
somewhat resembling oospores, in undoubtedly pure cultures of 
P. infestans. Whether they are oospores is not known. Clinton 
has recently announced ^^ that he, in pure cultures, has obtained 
"absolutely perfect oogonia, antheridia and even oospores." The 



Fig 




58. — Young and mature 
P. phaseoli. After Clinton, 



oospores 



THE FUNGI WHICH CAUSE PLANT DISEASE 



87 



oval, flattened biciliate zoospores which emerge from the conidia, 
swim about, come to rest, develop a wall, then produce a germ 
tube. Direct germination by a germ tube also occurs rarely. In- 




FlG. 



59. — P. infestans; 1, section showing conidiophores and conidia- 
formation; 5, germination of a conidia. After Scribner. 



fection is brought about by the germ tube, either by penetrating 
through stomata or directly through the epidermis. 

The walls and contents of parasitized cells are browned. When 
this fungus is alone on the tubers dry rot is induced, but invasion 
of numerous saprophytic fungi and bacteria usually turns this 
into a disagreeable wet rot. Tuber infection occurs largely from 



88 



THE FUxNGl WHICH CAUSE PLANT DISEASE 



conidia washed into the soil by rain; possibly sometimes by the 
mycelium migrating by way of the stem. 

The fungus was extensively studied by Jones in pure culture and 
a decided difference in luxuriance of growth was observed on blocks 
cut from different varieties of potatoes, Fig. 57. 

The mode of hibernation is not thoroughly known but undoubt- 
edly hibernation occurs in part in live mycelium in infected 
tubers.™ The conidia are short-lived, especially when dry. 

P. omnivora de Bary. Conidiophores simple or branched; 
conidia ovoid or lemon-shaped, 50-60 or even 90 x 35-40 fx, ger- 
minating by as many as fiftj^ zoospores; oospores smoothish or 
wrinkled, light-brown, transparent, 24-30 /jl. This species which 
includes forms previously described as P. cactorum (Lebert & 
Cohn) Schr., P. fagi Hartig, and P. sempervivi Schenk is found 
upon seedlings of some fifteen families ranging from Pinacse to the 
higher Angiosperms. It is of considerable economic importance 
in Europe especially in the seed beds of the forester. Recently it 

has been found on ginseng in 
Japan and the United States.^^ 
The same fungus is credited with 
destructive rotting of apples ^^ 
and pears ^^ in Europe and with 
causing two wide-spread tropical 
diseases, the cocoa pod rot and a 
palm disease. From the studies 
of de Bary ^^ and from the nature 
of the more recent outbreaks cred- 
ited to this fungus it appears that 
P. omnivora is a composite species 
which will eventually be segre- 
gated. Indeed segregation has 
already been begun. Coleman ^^ has described the palm in- 
fecting fungus of India as P. omnivora var. arecae while Maub- 
lanc ^^ has gone further and described the cocoa disease as P. 
faberi. See also "''> '^^^ 

P. sjrringae recently described by Klebahn is a closely related 
species, which is very destructive in the propagating beds of the 
lilac in Germany. 




Fig. 60. — Formation of swarm-spore 
of Phytophthora. After Smith. 



THE FUNGI WHICH CAUSE PLANT DISEASE 89 

P. agaves C{an.'^^ occurs on the Agave in Mexico. 

P. nicotiana v. B. d H.^*' is also closely related to P. omnivora, 
but culture work shows it to be rather fastidious in its choice of 
host as it attacks only tobacco seedlings. 

P. calocasiae Rac. occurs on Calocasia antiquorum in the Orient. 
An undescribed species on Castor is also reported.^^ 

Kawakamia Miyabi (p. 83) 

Mycelium slender, copiously branched; conidiophores single or 
in groups of 2-5 or more from the stomata, simple or sometimes 
irregularly branched, but branches never arising near the conidia. 
Conidia usually upon a slender pedicel cell, lemon-shaped, ob- 
tusely tipped, contents and wall colorless, germination normally 
by zoospores; zoospores oval, flattened and laterally biciliate; 
oospores spherical, smooth. 

A single species, K. cyperi (M. & I.) Miyabe,^^ which was intro- 
duced from Japan into Texas in imported plants of a sedge, 
Cyperus tegetiformis. The species is very destructive in Japan. 
Both conidia and oospores were produced in the Texan material.^^ 

Basidiophora Roze & Cornu (p. 83) 

B. entospora R. & C. occurs on species of Erigeron and culti- 
vated aster in Europe and America. 

Sclerospora Schroter (p. 83) 

This genus differs from all other Peronosporales in the pre- 
ponderance of its oospores; these are the conspicuous stage, while 
the conidiophores and conidia are few, small and evanescent. 
There are about five species. 

Mycelium much branched, with small vesicular haustoria; 
conidiophores erect, solitary or in groups of two or three, 
fugaceous, low and stocky, sparsely branched, the branches 
also stocky; conidia elliptic or globose-elliptic, hyaline, smooth; 
oospores globose, intramycelial, the epispore brown, irregularly 
wrinkled, permanently united to the persistent wall of the oogo- 
nium. 



90 



THE FUNGI WHICH CAUSE PLANT DISEASE 



S. graminicola (Sacc.) Sehr.,''-' ''^ infects leaves and inflorescences, 
the oospores causing marked distortion of the latter and rapid 
disintegration of the former; conidiophores 100 x 10-12 /x, conidia 
20 X 15-18 IX] oogonium wall thick, 4-12 n, at maturitj^ 30-60 n 
in diameter, reddish-brown; oospore pale-brown, 26-36 ii. 

The conidial phase is not prominent, while the oospores by their 
disintegrating effect upon the leaves of the host, render the plants 
quite conspicuous and closely simulate the habit of a brown smut. 




Fig. 61. — S. graminicola. 
Conidiophores and co- 
n i d i a ; germinating 
conidia and zoo- 
spores. After Butler. 




Fig. 62. — S. graminicola, oo- 
gonium, oospore and an- 
theridium in section. Af- 
ter Stevens. 



On millet (Setaria italica), pearl millet, fox tail and corn; in India 
of considerable economic importance.^^ 

S. macrospora Sacc. has been reported in com tassels and on 
wheat in Italy and the United States.^'^* ^^ Conidia unknown; 
oogonia embedded firmly in the tissue of the host, not causing 
disintegration as in S. graminicola; oospores light yellow, smooth, 
60-65 /i. 

Plasmopara. Schroter (p. 83) ^^^ 

The tree-like, branching conidiophores, Fig. 63, are common to 
this genus, Peronospora, Peronoplasmopara and Bremia, and 
unlike the conidiophores of Phytophthora they are completely 
formed before they begin to bear spores. 

Mycelium branched; haustoria simple; conidiophores erect. 



THE FUxNGI WHICH CAUSE PLANT DISEASE 91 

solitary or fasciculate, from the stomata of the host, monopodi- 
ally branched, the branches arising at right angles to the main 
axis, as do also the secondary branches (at least never appearing 
truly dichotomous) the ultimate branches apically obtuse; conidia 
globose to ovoid, hyaline or smoky, germinating by zoospores or 
the entire protoplasmic mass escaping and then sending out a 
germ tube; oospore globose yellowish-brown, the epispore va- 
riously wrinkled sometimes appearing somewhat reticulate; oogo- 
nium persistent, but free from the oospore. 

P. viticola (B. & C.).B. & d T,''- ''' "^' "'• ''' first collected in 
1834 by Schweinitz and regarded as a Botrytis was first published 
in 18515 

Hypophyllous, caulicolous, or on young fruits, covering the 
infected areas with a white downy growth; on the leaves epiphyl- 
lous discoloration yellowish ; on the fruit often causing a brown rot 
without producing conidia; conidiophores fasciculate, 250-850 x 
5-8 n, 4-5 times branched, the ultimate branchlets about 8 fj, long; 
conidia ovate-elliptic, very variable in size, 9-12 x 12-30 n; 
oospores 30-35 n, epispore brown, wrinkled, or almost smooth; 
oogonium thin-walled, hyaline or light yellowish-brown. 

The mycelium is found in all diseased tissues except the xylem. 
The conidiophores issue from stomata. The conidia germinate 
readily in water, producing in about three-fourths of an hour 
biciliate zoospores. These after fifteen to twenty minutes activity 
cease motion, round off, become walled, then germinate by a tube. 
This bores through the epidermis and develops into the internal 
mycelium. Infection is almost exclusively from the lower side of 
the leaf .^^ Oospores are much more rare than conidia but are often 
found in autumn, sometimes two hundred to a square millimeter of 
leaf surface. Though hibernation is doubtless chiefly by oospores 
it has been shown that the mycelium can perennate in old wood, 
and even form oospores therein. The fungus is dependent on 
abundant moisture. 

P. nivea (Ung.) Schr. attacks various species of umbellifers in- 
cluding the parsnip and carrot. It has been reported in America 
only from the region of San Francisco. 

P. halstedii (Farl.) B. & d T. 

This form is quite variable and should perhaps be separated 



92 



THE FUNGI WHICH CAUSE PLANT DISEASE 



into several distinct species. It is limited to the Compositse, 
Helianthus and Madia being the only hosts of economic impor- 
tance. 

Hypophyllous; conidiophores fasciculate, slender, 300-750 fx, 
3-5 times branched, ultimate branchlets 8-15 ju long, verticillate 




Fig. 63. — P. viticola. A, section of a leaf with conitliophores emerg- 
ing from a stoma; C, formation of swarm spores; D, formation 
of oospores. After Millardet. 

below the apex of the branching axis which is frequently swollen 
and ganghon-like ; conidia oval or elliptic, 18-30 x 14-25 /jl; 
oospores 30-32 n, epispore yellowish-brown, somewhat wrinkled. 

P. ribicola (Schr.) Schr. grows on various species of currants in 
Europe and America but is probably of but slight economic 
importance. 



THE FUNGI WHICH CAUSE PLANT DISEASE 93 

P. obducens (Schr.) Schr. occurs on Impatiens, both wild and 
cultivated, in North America, Europe and Asia. 

P. pygmea (Ung.) Schr. on various Ranunculacese, including 
Aconitum in Europe and cultivated Hepaticas in America,'''^ is 
of little economic importance. 

Peronoplasmopara (Berlese) Clinton (p. 83) 

There are three species which have been variously designated 
as Peronospora, Plasmopara, Pscudoplasmopara and Peronoplas- 
mopara. The genus combines colored conidia and zoosporic germi- 
nation with a type of conidiophores intermediate between those of 
Peronospora and Plasmopara. 

Mycelium much branched, haustoria small, usually simple; 
conidiophores pseudo-monopodially branched, the ultimate branch- 
lets acute, the primary arising at acute angles; conidia colored, 
elliptic, conspicuously papillate both apically and basally; oospores 
thin- walled, smooth or roughened; oogonium thin-walled. 

P. celtidis (Waite) Cl.^^ is unique in the family as the only 
species infecting dicotyledonous trees. It occurs on hackberry in 
the region about Chesapeake Bay, also in Japan. 

P. humuli Miy, & Taka ^" causes a serious hop disease in Japan. 
It has recently been found by Davis ^^ on wild hops in Wisconsin. 

P. cubensis (B. & C), CV'-'''' '°^ 

Hypophyllous, rarely amphigenous; discoloration of the host 
yellowish, or water-soaked; conidiophores 1-2 rarely more from a 
stoma, 180-400 x 5-9 fi, 3-4, rarely 2-5 times branched, the ulti- 
mate branchlets recurved; apically acute, 5-20 /x long; conidia 
gray, brownish or smoky, ovoid to ellipsoid, papillate, 20-40 x 
14-25 fi; oospores spherical, yellowish, warty-papillate, 30-43 fi, 
maturing in the decajdng leaves. 

The mycelium abounds in the spongy parenchyma. The 
conidiophores emerge through stomata, or rarely directly through 
the cuticle, near the invasion line of the fungus. Fresh conidia 
germinate in water in two to four hours forming fiattish zoospores 
with one anterior and one posterior cilium. The zoospores later 
become spherical, walled and develop a germ tube. These germ 
tubes enter the host through the stomata or directly through the 
cuticle from either above or below. Moist weather is favorable to 



94 



THE FUNGI WHICH CAUSE PLANT DISEASE 



the fungus in that conidia are produced more abundantly and 
retain their power of germination longer when moist. Disease 
spots appear two or three days after infection; conidia same nine 
or ten days after infection. 

The species is perennial in Florida ^'^ and spreads northward as 
the season advances, reaching Ohio and New York by late summer 




Fig. 64. — P. cubensis: 3. Conidiophore with young and 
old conidia. 5. Conidium. 6. Conidium germinating. 
11. Zoospores. 18. Infection through a stoma. 
After Clinton. 

or early autumn.^^ For a series of years after its discovery it was 
not well known even scientifically, its first serious outbreak being 
about 1889.^^ It appeared in Japan about the same time ^°° and 
is now known to be almost cosmopolitan. The oospores have 
been found only by Rostewzew and have not been seen in America. 
A wide range of wild and cultivated cucurbits is infected, among 




THE FUNGI WHICH CAUSE PLANT DISEASE 95 

them the pumpkin, squash, cucumber, muskmelon, watermelon, 
gourd, in fact according to the work of Selby ^^^ any cucurbit ap- 
pears liable to attack. Clinton infected muskmelons with spores 
produced on cucumber. The fungus is especially prevalent on 
cucumbers raised under glass. 

Bremia Kegel (p. 84) 

As in Peronospora except that just below the ends of the conidio- 
phore branches there are pronounced swellings from which spring 
radially a number of short branches each 
bearing an ovate, papillate conidium. The 
conidia germinate by apical germ tubes. 
There is only one species. 

B. lactucae Kegel is found on lettuce and 
several other Compositae.^"^ It is more in- 
jurious in Europe than in America. 

Hypophyllous or amphigenous, causing 

discoloration, then wilting of the host; conid- fig. 65. B.lactucEe. 

iophores produced singly but in great abun- After Tubeuf. 
dance, much branched; conidia ovate, 16-22 x 15-20 /x; oospores 
small, 26-35 n, light brown, the epispore wrinkled. 

Peronospora Corda (p. 84) ^- 

This genus of some sixty species contains several aggressive 
parasites. Its conidiophores are much like those of Plasmospara 
but with more tendency to dichotomous branching and to more 
graceful habit; the apices are acute. 

Mycehum well developed, haustoria filiform, simple or 
branched; conidiophores dichotomously 2-10 times branched at 
acute angles, ultimate branchlets acute, more or less reflexed; 
conidia hyaline or colored, papillate, germinating directly by lateral 
germ tubes; oospores globose, reticulate, tuberculate, wrinkled or 
smooth. 

P. parasitica (Pers.) De Bary.^^ This is often associated with 
Albugo Candida, giving it the appearance of a parasite on that 
fungus. Almost all species of Cruciferae are subject to attack, 
among them cabbage, cauliflower, radish, coUards, turnips, horse- 



96 



THE FUNGI WHICH CAUSE PLANT DISEASE 



radish, and others of minor economic importance. It is cos- 
mopohtan in distribution. 

The fungus covers any green part of the host with a dense white 
growth, often causing hypertrophy especially in oospore forma- 
tion; conidiophores 200-300 x 10-12 /i, bushy branched, stout, 
deliquescent, with 5-8 main branches, each from 3-7 times 
branched, ultimate branchlets slender, more or less curved, 
usually arising at acute angles, about 12-15 x 2-3 /x; conidia 
broadly elliptic, bluntish, often becoming globose, about 12-22 x 
24-27 IX, hyaline or very light; oospore 
globose, yellow-brown, 26-45 }x, epispore 
smooth or wrinkled; oogonium thick, color- 
less. 

P. effusa (Grev.) Rab. causes a serious 
disease of spinach. ^°^ It also occurs on a 
wide range of weeds of the Chenopodiacese. 
The species was formerly made to include 
all the effusse forms of the genus so that 
literature abounds with references to it on 
Viola, Plantago, Polygonum, etc. 

Hypophyllous, causing yellowish or brown- 
ish discolorations, the mass of conidiophores 
of a violet cast; conidiophores 150-400 x 
7-9 IX, much branched, the ultimate branches 
at right angles, usually recurved, 8-15 x 
3^ IX', conidia ellipsoid to globose 17-18 x 
22-24 IX, violet or smoky; oospores globose, 
30-40 IX, epispore light brown, more or 
less regularly wrinkled; oogonium thin, 
brown. 

P. schleideni Ung.^*^^ was first described as aBotrytis in 1841. 
It was noted in America in 1872 by Taylor, ^°^ later by Trelease ^°^ 
and by many others. ^°^ A very complete description was given 
by Whetzel ^°^ in 1904 under the name P. schleideniana. 

The conidia in mass present a purplish tint. The conidio- 
phores usually emerge singly through the stomata. The slender, 
branched haustoria abound in the parasitized part often with 
their ends wrapped around the nuclei. In water the conidia 




Fig. 66.— P 
spinach, 
sted. 



effusa on 
After Hal- 



THE FUNGI WHICH CAUSE PLANT DISEASE 97 

germinate directly to form an infective tube (Fig. 07) which 
grows into the stomata. According to Whetzel conidia retain 
their germinating power only a few hours. Shipley believed them 
viable for a much longer time.^"^ Fertilization occurs much as in 
P. parasitica (Fig. 67) and the sexual spores, which abound, 
serve for hibernation. They may live several years. 

It is found on onion, garlic, etc. (Allium sps.) everywhere, 
covering leaves with a dense growth; conidiophores, 3-6 femes 
branched, 300-700 x 12-15 /x; branches 2-5, scattered, ultimate 
branchlets subulate, 15-20 /jl, more or less recurved; conidia large, 
obovate to pyriform, basally papillate, 45-58 x 20-25 [jl, the 
membrane violet; oospore globose, light-brown, about 30 ju, 
epispore smooth or slightly wrinkled. 

P. sparsa Berk, is parasitic on roses ^^ and constitutes a serious 
pest in Europe, though not so common in America. 

Hypophyllous, with a whitish growth; conidiophores about 
9 times branched, the ultimate branchlets reflexed; conidia sub- 
elliptic, pale gray. 

P. trifoliorum de Bary. Hypophyllous, forming a dense grayish 
or dirty- white growth over the host; conidiophores slender, 360- 
600 X 9-11 M, 6-8 times branched at acute angles, the primary 
branches rather erect, the secondary more spreading, flexuose, more 
or less recurved, ultimate branchlets at right or obtuse angles, 
straight, subulate, 7-12 x 7-3 /x; conidia globose to broadly elliptic, 
15-20 X 18-36 iJL, violet; oospores globose, 24-30 n, epispore light 
brown, smooth. 

It causes serious loss to clover in Europe. Species of related 
genera also suffer. Recently it has assumed a role of importance 
in America by its attacks upon Alfalfa ^^° on which it occurs from 
New York to California. 

It differs from P. vicise in the branching of the conidiophores, 
the lighter color of the spot and fungus, and the smooth oospores. 

P. viciae Berk. Hypophyllous or cauHcolous, covering the host 
with a grayish-violet growth, epiphyllous discolorations yellowish 
or inconspicuous; conidiophores fasciculate, 300-700 x 9-11 fi, 
5-8 times branched, the main branches arising at acute angles, 
erect, the ultimate subequal, slightly flexuose, arising at right or 
obtuse angles, the lateral recurved, 10-17 x 2-3 n; conidia elliptic 



98 



THE FUNGI WHICH CAUSE PLANT DISEASE 




14 15 

Fig. 67. — P. schlcideni. 11. Mycelial threads between the large conductive cells of 
the leaf; (a) the mycelial thread; (b, b) branched or coiled haustoria; (c) branched 
haustorium wrapped about the nucleus. 13. Young eonidiophores, (a, a) turn- 
ing toward the stoma, (b); (c) haustorium wrapped about the nucleus of the 
epidermal cell. 14. Mature conidiophore (a) with mature conidia, (c, c); 
(d) germ tube of conidium entering stoma. 15. Oospores, (a) mature oospore 
with old antheridium, (d) still attached; (b) mature oospore still inclosed in the 
old wall of the oogonium. After Whetzel. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



99 



or obovoid, 15-20 x 21-28 /x, light-violet; oospores small, 25-30 fx, 
epispore yellowish-brown, with low, broad reticulations, areola? 
about 8 n; oogonium thin, fugaceous, 32-40 /x. 

This fungus on Mcia and related genera is sometimes quite 

A 




Fig. 68. — A sporangium with a columella (Mucor). 
After Sachs. 

serious, particularly on vetch and peas in Europe, Asia and 
America. 

P. violae de Bary ; on cultivated violets and the pansy in Europe 
and America, ^^ forming discolored spots; foUicolous or caulicolous, 
with a pale violet growth, conidiophores fasciculate, short, 2-7 
times dichotomously branched; ultimate branchlets short, sub- 
ulate, reflexed; conidia elliptic, short, apiculate, 20-22 x 15-18 /x, 
violet. 



100 



THE FUNGI WHICH CAUSE PLANT DISEASE 



P. dipsaci Tul. on teasel and Scabiosa in Europe and America and 
P. violacea Berk, on the flowers of species of Scabiosa in Europe 
are quite distinct from the preceding; P. schachtii Fcl. on beets 
kills seedlings in Europe. P. linariae Fcl. is on digitalis; P. cytisi 







Fig. 69. — Sporophores in the Zygomycetes. After De Bary, 
Brefeld, Cunningham, Schrotor. 

Rost."^' ^^- on species of Cytisus in Europe; P. arborescens (Berk.) 
de Bary on poppies, especially garden seedlings, in Europe and 
Asia. 

Species of less importance are: 

P. rubi Rab. on various species of Rubus in Europe and 
America; P. fragariae R. & C, usually cited as a synonym of 
P. potentillse de Bary, on the strawberry in France and America; 
P. trichomata Mas.^^''' ^^^ the cause of a root rot of Colocasia 



THE FUNGI WHICH CAUSE PLANT DISEASE 



101 




Fig 



foMiuition. 



in the West Indies; P. Candida Fcl. on the primrose in Europe 
and upon non-economic Primulaceae in America; P. maydis Rac.^^^ 
the cause of a disease of corn in Java. [Its identity with Sclero- 
spora graminicola is suggested by the recent studies of that species 
by Butler.] P. vincae Schr. on Vinca minor in Europe; P. myoso- 
tidis de Bary on several species 
of forget-me-not and related 
genera in Europe and America; 
P. cannabina Otth. on hemp in 
Europe and Japan; P. con- 
glomerata Fcl. upon alfilaria 
in Europe; P. ficariaB Tul. on 
various species of Ranunculus 
both in the old and the new 
world; P. antirrhini Schr. on 
the snapdragon and related 
hosts in Europe; P. nicotianae 
Speg.-^^^ on various ornamental 
species of Nicotiana in South 
America and California; P. Va- 
leria mellae Fcl. in Europe on Valerianella; P. Valerianae Trail on 
Valerian; P. dianthi de Bary on species of Dianthus in Europe; 
P. corallae Tranz. on Campanula in Europe; P. jaapiana ^^" on 
rhubarb in Europe; P. phoenixae Tap. on Phoenix ^^^ and an un- 
determined species on Para rubber. 

Mycelophagus castaneae Man."^ is an imperfectly described 
form which may belong either to the present group or to the 
Chytridiales. A serious disease of the chestnut in France is 
charged to it. 

Zygomycetes (p. 66) 

This group of fungi is readily distinguished from the Oomycetes 
by its isogamous sexual organs, when these are present. In the 
absence of sexual organs the general type of sporangium is usually 
sufficient mark of distinction for those who are even but slightly 
acquainted with the two groups. The mycelium, if young, serves 
to indicate relationship to the Phycomycetes. Older mycelium is 
often septate and would lead the unwary into errors of classification. 



-Mucor: zygospore 
After Brefeld. 



102 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Asexual spores are either in sporangia or are borne as conidia. 
The sporangium is usually with a columella. The spore-bearing 
stalks exhibit the widest diversity in shape and form of branch- 
ing, Fig. 69. 

Sexual spores (zygotes) are produced through the union of two 
like gametangia. (Fig. 70.) Though the cytology of zygote 
formation has not been completely studied it seems clear that the 
fertilization is multi -nucleate ^^'^ as in Albugo bliti and that the 
two uniting elements are coenogametes. 

Key to Orders of Zygomycetes 

Asexual spores borne in sporangia which 

in some genera are reduced to 

conidia-like bodies 1. Mucorales, p. 102. 

Asexual spores true conidia borne singly 

at the apex of the conidiophores . ... 2. Entomophthorales, p. 107. 



Mucorales (p. 66) 

This order is comprised mainly of saprophytes, about twenty 
genera and one hundred fifty species; but includes a few forms 

which prey upon vegetation in a very 
low ebb of life, as cells of ripe fruit, 
tubers, etc., and a few species which 
are of especial interest as they grow 
upon other fungi. The sporangial 
stage is exceedingly common; the 
zygosporic much less so, very rare in 
the case of some species. Blakeslee ^-° 
has shown that in some species, 
though the two uniting sexual organs 
Fig. 71.— Phyroinycctos showing are to all appearances alike, the plants 

zygosporic lines at regions of . ,. ,. . 

contact between + and — are in reality dioecious; that a branch 

strains. After Blakeslee. c i j. j. i i 

from one plant cannot produce sexual 
organs that will unite with other sexual organs produced upon 
the same plant. Moreover, there appears to be a differentia- 
tion of sex in that one plant, which may provisionally be re- 




THE FUNGI WHICH CAUSE PLANT DISEASE 103 

garded as the male, unites freely with another plant, provisionally 
the female, but this male plant refuses to unite with any other 
plant which is capable of uniting with the female and all plants 
that can unite with the male refuse to unite with the females. In 
some species the plants of one sex show a more luxuriant vegeta- 
tive growth than do plants of the other sex. 

Key to Families of Mucorales. 

Asexual spores in typical sporangia, although 
in some genera few-spored 
Sporangium with columella;- zygospores 
naked or tliinly covered with out- 
growths of the suspensor 1. Mucoraceae, p. 103. 

Sporangium without a columella; zygo- 
spores closely covered by hyphae ... 2. Mortierellaceae. 
Asexual sporangia monosporic and conidia- 
like, sometimes accompanied by larger 
polysporic sporangia 
Sporangia of two kinds, polysporic and 

monosporic. 3. Choanephoraceae, p. 106. 

Sporangia all monosporic; parasitic on 

other genera of Mucorales 4. Chaetocladiaceae. 

Sporangia simulating chains of conidia. . 5. Piptocephalidaceae. 

Of these families the second and fifth are pure saprophytes, 
while the fourth is parasitic upon other members of the order. 

Mucoraceae 

Mycelial threads all alike or of two kinds, one aerial, the other 
buried in the substratum, coenocytic during growth but septate 
at maturity; reproduction by asexual spores borne in sporangia 
and by zygospores formed by the union of equal gametes; spor- 
angiophores, simple or branched; sporangia variable, typically 
with a columella, and many spores but in some genera some of 
the sporangia are few-spored and without columellas; zygospores 
variable, smooth or spiny, borne on short branches of the myce- 
lium. 



104 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Key to Subfamilies and Genera of Mucoracese 

Sporangial membrane cuticularized and per- 
manent above, thin and fugaceous be- 
low Subfamily I. Paoboleae. 

Sporangiopliore of equal size throughout; 

spore mass not forcibly discharged . . . Pilaira. 
Sporangiopliore swollen beneath the spo- 
rangium; spore mass forcibly dis- 
charged at maturity Pilobolus, p. 105. 

Sporangial membrane thin and fugaceous 
throughout 

Sporangia all similar Subfamily II. Mucoreae. 

Mycelium differentiated into a colorless 
vegetative and a colored aerial re- 
gion 
Aerial mycelium stoloniferous, zygo- 
spores formed in the substratum 
Sporangiophores arising from the 

nodes 1. Rhizopus, p. 105. 

Sporangiophores arising from the 

internodes 2. Absidia. 

Aerial mycelium not stoloniferous; 
zygospores aerial 

Sporangiophores simple 3. Spinellus. 

Sporangiophores dichotomously 

branched 4. Syzygites. 

Mycelium undifferentiated 

Mycelium gray or brown; suspensors 
smooth 

Sporangiophores simple 5. Mucor, p. 106. 

Sporangiophores variously branched 

Sporangia borne apically on the 

sporangiophore and its 

branches 

Zygospores formed from equal 

gametes 6. Calyptromyces. 

Zygospores formed from un- 
equal gametes 7. Zygorhynchus. 

Sporangia borne only on the 
lateral, circinate branches of 
the sporangiophore 



THE FUNGI WHICH CAUSE PLANT DISEASE 105 

Sporangia globular; columella 

not constricted 8. Circinella. 

Sporangia pear-shaped ; colu- 
mella constricted 9. Pirella. 

Mycelium metallic; suspensors spiny 10. Phycomyces. 
Sporangia of two kinds, the primary 
many-spored; the secondary few- 
spored Subfamily III. Thamnidieae. 

Pilobolus crystallinus (Wigg.) Tode, a form with beautiful 
crystalline sporangia on yellowish, evanescent sporangiophores has 
been frequently noted as injuring or smudging chrysanthemum, 
rose and other leaves 121-122 j^y j^g profuse discharge of spo- 
rangia. It is not, however, a parasite. 

Of the other genera the only ones of interest regarding plant 
disease are Rhizopus and Mucor. The others are saprophytes found 
on a great variety of substances, manure, fungi, and many other 
kinds of organic matter. 

Rhizopus Ehrenberg (p. 104) 

The sporangium wall is not cutinized, and falls away. The 
sporangia are all of one kind and with columellas. The sporan- 
giophore is never dichoto- 
mous; zygotes are found in the 
mycelium. The suspensor is 
without outgrowths. Twelve 
or fifteen species, chiefly sap- 
rophytes. 

R. nigricans Ehr. Aerial 
mycelium at maturity choco- ,, „„ ^, . -^. 

. . riG. 72. — Rhizopus. Diagram showing 

late-colored; rhlZOlds numer- mycelium and sporophores. After Coul- 

1 r • ter, Barnes and Cowles. 

ous; sporangiophores fascicu- 
late, erect, aseptate; sporangia globose, blackish-olive, granular; 
columella hemispheric; spores gray to brown, subglobose or irregu- 
lar, 11-14 /x; zygospore 150-200 n, epispore with rounded warts, 
black. This is the cause of soft rot of stored vegetables, particu- 
larly of sweet potatoes,^^^also of Irish potatoes, ^^^ apples and pears; 
it causes death of squash blossoms ^^'^ and is destructive to barley 




106 THE FUNGI WHICH CAUSE PLANT DISEASE 

during malting. It is distinctly a wound parasite and is unable 
to force entrance through a sound epidermis. 

The richly branched mycelium which varies from very thin and 
hyaline to thick, coarse and slightly fuscous, is found throughout 
the rotten portion of the host. After a period of luxuriant vegeta- 
tive growth hyphae protrude to the air, first through existing 
ruptures in the epidermis, later by rifts forced by the fungus 
itself. Sporangiophores then form in dense bush-like growths, 
each sporangiophore bearing one terminal sporangium. The 
sporangia are at first white, later black and contain very numerous 
spores. Spore formation has been closely studied by Swingle. ^^^ 
Aerial stolon-like hyphae reach out in various directions and at 
their points of contact with some solid develop holdfasts (Fig. 72) 
and a new cluster of sporangiophores. 

Zygotes are produced by union of two mycelial tips as is shown 
in Fig. 70. 

Orton ^-^ inoculated pure cultures of this fungus on sterile raw 
Irish potato and induced typical decay. He also noted that there 
was a difference in the rate of decay produced by strains of Rhizo- 
pus derived from different sources and that the most rapid decay 
of potatoes was caused by strains taken from rotting potatoes. 

R. necans Mas.^^^ causes decay of lily bulbs in Japan. 

R. schizans Mas. is cited as the cause of split-stone in peach. ^^^ 

Mucor Linnaeus (p. 104) 

Mycelium all of one kind, buried in the substratum or grow- 
ing over its surface; sporangiophores scattered or not, simple 
or branched; sporangia globose; columella cylindric, pyriform or 
clavate; spores numerous, variable; zygospores globose, smooth or 
warty. 

Some thirty species, chiefly saprophytes. 

M. mucedo L. is destructive to beech nuts in winter. 

M. pyriformis Fisch and M. racemosus Fes. cause decay of 
fruits. 

Choanephoraceae (p. 103) 

Mycelium parasitic on living plants; sporangia of two kinds; 
macrosporangia globose, columella small, spiny, spores few, on 



THE FUNGI WHICH CAUSE PLANT DISEASE 107 

simple or branched, erect sporangiophores ; microsporangia clavate, 
one-spored simulating conidia and borne in heads on the enlarged 
apices of umbellately branched sporangiophores; zygospores as 
in Mucoracae. 

A single genus, with three species. 

Choanephora infundibulifera (Curry) Sacc. and C. americana 
A. Moll occur on blossoms in India and South America. 

A third species, C. cucurbitarum (B. & Br.) Thaxter, is the 
cause of decay of cucurbits especially pumpkins, in the eastern 
and southern states. ^-^ 



Entomophthorales (p. 66) 

This order is predominately one parasitic on insects. Some 
fifty species are known, only four of which are plant parasites. 
Asexual reproduction is chiefly by conidia, apically borne and for 
the most part forcibly ejected from their stalks at maturity. 

Key to Families of Entomophthorales 

Endozoic parasites (Insecta, Arachnoidea) . 1. Entomophthoraceae. 
Endophytic or saprophytic 2. Basidiobolaceae, p. 107. 

Basidiobolaceae 

This family is characterized chiefly by its habitat. Septa are 
numerous in the vegetative mycelium. 

Key to Genera op Basidiobolaceae 

Intracellular parasites, the mycelium greatly 

reduced 1. Completoria, p. 108. 

Saprophytes, or parasites on higher fungi, 
the mycelium well developed. 
Conidia produced directly from an un- 
swoUen conidiophore. Parasites on 

higher fungi 2. Conidiobolus. 

Conidia cut off from the apex of a swelling 

of the conidiophore. Saprophytic. . . 3. Basidiobolus. 



108 THE FUNGI WHICH CAUSE PLANT DISEASE 

With the exception of the one species given below these are not 

parasitic on higher plants. 

Completoria complens Lohde is parasitic upon fern prothallia,^^'^ 
Vegetative body compact, of oval or curved branches in a single 

host cell, extending to other cells by slender tubes. Resting spores 

10 to 20, formed in the host cell. Propagation by non-motile 

conidia, 15-25 fx, in diameter. 



BIBLIOGRAPHY OF PHYCOMYCETES * 

(pp. 59-108) 

1 Atkinson, G. F., Ann. Myc. 7: 441, 1909. 

2 Stevens, F. L. and Hall, J. G., Bot. Gaz. ^8: 1, 1909. 

3 Bessey, Ernst, Diss, Halle, 1904. 

4 Smith, E. F., B. P. I. B. 17: 13, 1899. 

6 Milburn, Thomas, C. Bak. 13: 129, 257, 1904. 
8 Woronin, Jahrb. Wiss. Bot. 11: 556, 1878. 

7 Home, A., Ann. Myc. 7: 286. 

8 de Wildeman, E., Mem. Roy. Belg. Soc. Micr. 21, 1893. 

9 Stevens, F. L., Bot. Gaz. 35: 405, 1903. 
" Stevens, F. L., Ann. Myc. 5: 480, 1907. 

11 Griggs, R. F., Bot. Gaz. 48: 339, 1909. 

12 Kusano, C. Bact. 19: 558, 1907. 
" Percival, C. Bak. 25: 440, 1910. 

1" Schilberszky, Ber. Deut. Bot. Gez. V^: 36, 1896. 
15 Zimmermann, E., Nat. Zeit f. Forst u. Land. 8: 320, 1910. 
i« Salmon, E. S. & Crompton, T. E., Wye Ag. Coll. R. Ec. Myc. 109, 
1908. 

17 Thomas, Insect Life 1: 279, 1884. 

18 Halsted, B. D., N. J. B. 6^: 4, 1889. 
" Shear, C. L., B. P. I. 110: 37, 1907. 

20 Farlow, W. G., Bull. Bussey Inst. 2: 233, also Bot. Gaz. 10: 239, 1885. 

21 Nowakowski Beitrag. Kennt, Chytrid. 1876. 

22 Berlese, A. N., Riv. Path. Veg. 7: 167, 1901. 

23 C. R. 119: 572, 1894. 
2" C. R. 120: 222, 1894. 

25 Ellis and Barthohnew, Trans. Kan. Acad. Sci. 16: 167, 1899. 

2" B. My. d. Fr. 26: 

27 C. R. 119: 108, 1894. 

2s Magnus P. Ann. Bot. 11: 92, 1897. 

23 Massee, Bull. Kew Garden, 1906. 

3» Magnus, P. Ber. Deutsch. Bot. Ges. 20: 291, 1902. 

'1 Sydow. Ann. Myc. 1: 517, 1904. 

'2 Farlow, W. G., Rhodora 10: 9, 1908. 

*See footnote, page 53. 
109 



no THE FUNGI WHICH CAUSE PLANT DISEASE 

33 Atkinson, G. F., N. Y. (Cornell) B. 94, 1895. 

3* Mass. Agr. Exp. Sta. R. 8: 220, 1890. 

35 Miyaki, Ann. Bot. 15: 653, 1901. 

38 Butler, E. J., Mem. Dept. Agric. India, Botan. Ser. 15: 86-91, 1907. 

37 Halsted, B. D., N. J. R. 13. 

38 Butler, E. J., R. Pusa. 10: 44, 1909. 

^' Smith, E. H. & Smith, R. E., Bot. Gaz. 42: 215, 1909. 

« Smith, R. E., Cal. B. 190. 

"1 Stevens, F. L., Bot. Gaz. 32: 77, 1901. 

« Stevens, F. L., Bot. Gaz. 28: 149, 1899. 

« Davis, B. M., Bot. Gaz. 29: 297, 1900. 

" Wager, H., Ann. Bot. 10: 295, 1896. 

45 Wilson, G. W., Torr. Bull. 34: 61, 1907. 

« Melhus, I. E., Sc. 33: 156, 1911. 

« Halsted, B. D., N. J. R. 11: 350, 1890. 

48 Stewart, F. C., N. Y. (Geneva) B. 328, 1910. 

« Halsted, B. D., N. J. B. 76: 1890. 

M Pammell, L. H., la. B. 15: 236, 1891. 

" Halsted, B. D., N. J. R. 15: 355, 1894. 

62 Ruhland, Diss., 1903. 

53 Stevens, F. L., Bot. Gaz. 34: 420, 1902. 

54 Wilson, G. W., Torr. Bull. 34: 387, 1907. 

55 J. Myc. 13: 205, 1907. 

5" Clinton, G. P., Ct. R. 329, 1904. 

57 Berlese, A. N., Riv. d. Pat. Veg. 9: 1, 1900; 10: 185, 1902. 

58 Thaxter, R., Bot. Gaz. U: 273, 1889. 

59 Thaxter, R., Ct. R. (State) Sta. 167, 1899, 1890. 
6" Scribner, F. L., D. Agr. R. 337, 1888. 

61 Lodeman, E. G., N. Y. (Cornell) Bui. 113: 249, 1896. 

62 Sturgis, Bot. Gaz. 25: 191, 1898. 
«3 Clinton, G. P., Ct. R. 278, 1905. 

64 Smith, R. E., Cal. B. 175, 1906. 

65 Smith, W. G., Card. Chron. 1875. 

66 Smith, W. G., Quar. Jour. Mic. Sc. 15: 1875. 

67 Smith, W. G., Diseases of Crops, 1884. 

68 Jones, L. R., Sc. 29: 271, 1909. 

69 Clinton, G. P., Sc. 33: 746, 1911. 

'« Clinton, G. P., Ct. R. 362, 1904; also R. 304, 1905. 

71 Whetzel, H. H., Sc. 31: 790, 1910. 

72 Osterwaldc, A., C. Bak. 15: 434, 1906. 

73 Bubak, Fr., Zeit. 20: 257, 1910. 



BIBLIOGRAPHY OF PHYCOMYCETES 111 

'* de Bary, A., Bot. Zeit. 587, 1881. 

" Coleman, L. C, Mycol. Bull. 2: Dept. Agric. Mysore State, 1910. 

™ Maublanc, L'Agr. Prat. d. Pays Chauds 79: 315, 1909. 

" Ridley, H. N., Agr. B. Straits & Fed. Maley Sts. 10: 70, 1911. 

'8 Petch, T., Circ. and Agr. J. Roy. Bot. Gard. Ceylon 5: 143, 1910. 

" Gandary, G., Mem. Y. Rev. Soc. Cient "Antonio Alzate" 25: 293, 
1909. 

«o Meded, Lands. Plant. Batavia IS: 189G. 

81 Butler, E. J., Rept. Agr. Research Inst. Pusa 10: 45, 1909-1910. 

8= Patterson, F. and Charles V. K., B. P. I. 171: 1910. 

8^ Kawakamia, a new genus belonging to Peronosporacea? on Cyperus 
tegetiformis. With a postscript by Dr. Khigo Miyabe, 1904. 

" Butler, E. J., Mem. Dept. Agric. India, 2: No. 1, 1907. 

85 Cugini, G. and Traverso, G. B., Staz. sperim. Agr. Ital. 35: 46, 1903. 

86 Peglion, C. Bak. 28: 580, 1910. 

" Berkeley, J., Hort. Soc. Lond. 6: 289, 1851. 

88 Dept. Agr. R. 96, 1886. 

89 Appel & Riehm, Ber d. Kais. Biol Ans. f . L. u. F. Heft, 8, 1908. 

90 Stewart, F. C, N. Y. (Geneva) B. 32S: 352. 

91 Waite, M. B., Journ. Myc. 7: 105, 1902. 

92 Miyabe, K., Trans. Sappora Acad. Sci. 1: 1909. 

93 Davis, J. J., Science, 31: 752, 1910. 

9" Clinton, G. P., Ct. R. 336: 1904, 1905. 

95 Rostewzew, Ann. Inst. Agron. Moscow, 9: 47 and Flora 92: 405, 1903. 

9« Clmton, G. P., Ct. R. 23: 277, 1899. 

9' Hume, H. H., Fla. R. 30, 1900. 

98 Orton & Garrison, S. C. B. 116: 7, 1905. 

99 Halsted, B. D., Bot. Gaz. U: 149, 1889. 

100 Farlow, W. G., Bot. Gaz. 14: 187, 1889. 
"1 Selby, A. D., Bot. Gaz. 27: 67, 1909. 

102 Stewart, F. C, N. Y. (Geneva) B. 119: 158. 1897. 

103 Arthur, J. C, N. Y. (Geneva) R. 4: 253, 1885. 
10^ Halsted, B. D., N. J. B. 70. 

105 Whetzel, H. H., N. Y. (Cornell) B. 21S: 1904. 
108 Taylor, T. R., D. Agr. 193, 1872. 

107 Trelease, Wm., Trans. Wis. Acad. Sc. 6: 7, 1881-1884. 

108 Wis. R. 16: 34, 1883. 

109 Shipley, A., B. 19: Miss. Kew. 1887. 

110 Stewart, F. C, French, G. T., & Wilson, T. K., B. N. Y. (Geneva) 
305: 394, 1908. 

111 Rostrup, Zeit. 2: 1, 1892. 



112 THE FUNGI WHICH CAUSE PLANT DISEASE 

112 Magnus, P., Hedw. 149, 1892. 

1" Massee, G., Jour. Linn. Soc. Bot. 24: 48, 1887. 

114 Barrett, O. W., R. Porto Rico 398, 1904. 

115 Raciborski, M., Ber. d. Deut. Bot. Ges. 15: 475, 1897. 
11° Spegazzini, C., Rev. Argent. Hist. Nat. 1: 36, 1891. 

1" Magnus, P., Ber. d. Deut. Bot. Ges. 28: 250, 1910. 

118 Taplin, W. H., Amer. Florist 21: 587. 

115 C. R. Acad. Sci. Paris, 136: 472, 1906. 

120 Blakeslee, A. F., Proc. Acad. Art. & Sci. 40: 1904. 

"1 Halsted, B. D., Amer. Flor. 13: 117. 

122 Stewart, F. C., N. Y. (Geneva) B. 328: 342. 

123 Halsted, B. D., N. J. B. 76': 1890. 
12* Orton, W. A., Sc. 29: 916, 1909. 

125 Kirk, T. W., N. Zeal. D. Agr. R. 77: 1909. 

126 Swingle, D. B., B. P. I. 37: 1903. 

127 Kew Bull. 871, 1897. 

128 Rept. Mic. Vio., N. S. Wales, 1909. 
123 Thaxter, R., Rhodora 99: 1903. 

i3« Atkinson, G. F., N. Y. (Cornell) B. 94: 252: 1895, also Bot. Gaz. 
19: 47, 1894. 

131 Gussow, Ottawa B. 63, 1909. 

"2 Trow, A. H., Ann. Bot. 18: 541, 1904. 

133 Idem, 15: 269, 1901. 

13" Rosenberg, 0., Bihand till K. Svens Vet. Akad. Handl. 28: 10, 1903. 

135 Gruber E., Ber. d. Deut. Bot. Gaz. 19: 51, 1901. 

136 Edgerton, C. W., La. B. 126: 1911. 
13' Smith, E. G., Sc. 30: 211, 1909. 

138 McCallum, W. B., Ariz. R. 583, 1909. 

139 Halsted, B. D., N. J. R. 1893, 393. 

i« Stevens, F. L., Bot. Gaz. 38: 300, 1904. 

1" Bubak, Fr., C. B. 8: 817, 1902. 

"2 Magnus, P., C'. Bak. 9: 895, 1902. 

1" Farlow, W. G., Bus. Inst. 1: 415, 1871. 

14" Scribner, F. L., D. Agr. R. 96, 1886 and 88, 1887. 

i« Stewart, F. C., Eustace, H. J. & Sirrine, F. A., N. Y. (Geneva) B. 
241: 1903. 

i"6 Morse, W. J., Me. B. 169: 1909. 

i« Jones, L. R., Vt. B. 72: 1899. 

i"8 Stewart, F. C., Eustace, H. J. and Sirrine, F. A., N. Y. (Geneva) B. 
264: 1904. 

i« Fariow, W. G. B. Bussey, Inst. 415, 1876. 



ASCOMYCETES (p. 64) ^' ''• "• ^^' "' "• "• *^ 



The distinguishing mark of this group is the ascus. This in its 
typical form is shown in Fig. 73, as a long, slender or club-shaped 
sac in which the spores are borne. The number of spores in the 
ascus is usually definite and is commonly of the series, 1, 2, 4, 8, 
16, 32, 64, etc., the most common number being 8. The spores 
vary in size, color, shape, markings and septation. The asci 
in most genera are arranged in a definite group, a layer, con- 
stituting the hymenium which may be either 
concave, convex, or flat. Between the asci in the 
hymenium are often found slender hyphal threads 
of various form, the paraphyses, Fig. 73. 

The hymenium may be borne in or upon a 
firm substratum of woven threads, the stroma, 
or upon a very tenuous substratum, the subicu- 
lum, or without any definite subascal structure. 
The stromata vary widely in character, size, tex- 
ture, color, surface, form, etc. 

The mycelium is usually abundant, branched 
and septate, the septation readily distinguishing 
this group from the Phycomycetes. In many 
species the mycelium weaves together into a false 
parenchyma and constitutes relatively large -p^^ -3 _ portion 
spore-bearing structures. Fig. 74. 0/ a hymenium 

. showing asci and 

ihe ascigerous organ, ascocarp, or ascoma, paraphyses. Af- 
if saucer-shaped and open is an apothecium, ^""'^ Chamberlain. 
Fig. 92; if closed a perithecium, Fig. 144. In other cases, the 
ascigerous layer covers the exterior surface. Fig. 74. 

On the boundary lines between the Ascomycetes and other groups 
are fungi which do not present the typical Ascomycete picture 
but which are regarded as probably belonging to the group, i. e., 
transition forms between this and other groups. Among such are 

113 




114 



THE FUNGI WHICH CAUSE PLANT DISEASE 



forms in which the asci are without either stroma or covering, 
(Protodiscales, p. 125) ; others in which the asci are not even in 
groups but are scattered irregularly throughout the ascocarp 
(Aspergillales, p. 164); and still others with the asci neither in 
regular groups nor covered (Protoascomycetes, p. 119). One 
further deviation from the typical form occurs in the Hemiascomy- 




FiG. 74. — The large ascocarp of the morel. After Freeman. 



cetes which possess a sporangium-like structure resembling that 
of the typical Zygomycete; but a mycelium like that of the typical 
Ascomycetes. This is by many regarded as the transition form 
bridging the gap between and indicating the kinship of these two 
groups; a view strongly supported by the existence of very similar 
sexual processes in the two groups. 

Besides the ascus the Ascomycetes possess many other kinds of 



THE FUNGI WHICH CAUSE PLANT DISEASE 



115 



reproductive structures in the form of conidia. These may be 
borne singly or in rows on simple or branched conidiophores. 

The conidiophores may be single or variously grouped in columns 
or layers. Figs. 352, 378, 382. In some instances they are very 

,an 




H 



Fiu. 75. — Sphaerotheca castagnei. Fertilization and de- 
velopment of the perithecium. Og= oogonium, an = 
antheridium, st= stalk-cell. 6 as the ascogonium 
derived from the oogonium. After Harper. 

short, innate; again they are long, loose or floccose. They may 
emerge through stomata singly or in tufts or they may form sporo- 
genous cushions below the epidermis or again they may be borne 
inside of a hollow structure, the pycnidium, which covers them. 
Chlamydospores are also found. 
One or several distinct types of 
sporification may belong to one 
species of Ascomycete. These dif- 
ferent forms of spores may appear 
simultaneously on the same myce- 
lium or they may follow in definite 
succession regulated by the changes 
in environment, or again one or 
more of the spore forms belonging to the life history of the fun- 
gus may be omitted for long intervals to appear only as the 
result of stimuli of which little is yet known. 

The conidia and chlamydospores are asexual spores. Sexuality 



u 



Fig. 76. — Boudiera. Six sets of 
sexual organs. After Claussen. 



116 



THE FUNGI WHICH CAUSE PLANT DISEASE 



■-PxH 



in the great majority of Ascomy- 

cetes has not been investigated; 

but in some species fertilization is 

/ 7^ known to occur ; in many species, 

at least in form similar to that 
shown by the Phycomycetes, it is 
absent, probably having been lost 
by degeneration or else very much 
modified. 

In some of the Discomycetes 
^ „^ T . - . u • • there is one or more carpogonia 

Fig. 77. — Later stage showing asci ... . . 

and ascophores. After Claussen. and fertilization is through a tri- 
chogyne by spermatia; a mode often met among the lichens. 

In Pyronema,^ Fig. 78, the carpogonium is multi-nucleate and it is 
fertilized by a multi-nucleate antheridium through a trichogyne. Fu- 



C--: 



/ <^ 






YrmJM 






J? ^ B . . 

Fig. 78. — Pyronema eonfluens. A. the sex organs, og = oogonium, t= trichogyne. 
B. fertilization stage in section through young apothecium, asc=asci, asf=a8- 
cogenous filament. After Harper. 

sion of nuclei is probably in pairs as in Albugo bliti of the Phycomy- 
cetes. In Boudiera" a very similar relation is found. Figs. 76, 77. 

In some Perisporiales ^ an uninucleate oogonium is fertilized by 
an uninucleate antheridium. Fig. 75. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



117 



The oogonium after fertilization gives rise to a more or less 
complicated system of ascogenous hyphae, very simple in the 
Erysiphacese, very complex in some Discomycetes, which produces 
the asci. The sterile parts of the ascocarp, the paraphyses and 
enveloping structures, arise from parts below the oogonium and 
antheridium. 

The very young ascus usually receives two nuclei from the parent 
strand of the ascogenous hypha. These nuclei unite giving the 




Fig. 79. — Tip of ascus 
of Erysiphe showing 
delimitation of asco- 
spore from asco- 
plasm by astral 
rays. After Harper. 




Fig. >sU.— Later .sta^o than 
fig. 79, showing well de- 
fined spore-wall. After 
Harper. 



primary-ascus-nucleus. This by successive mitoses affords the 
single spore-nuclei. The spores are cut out from the protoplasm 
of the ascus in a most peculiar manner by reflexion of and union 
of astral rays which emanate from a centrosome-like organ at the 
beak of the prolonged nucleus. Figs. 79, 80. 

The significance of two nuclear fusions in the life cycle of these 
fungi, one following the union of the antheridium with the oogo- 
nium, the other later, in the asci, is a puzzling phenomenon, the 
real significance of which is not clear. 

Key to Subclasses of Ascomycetes 
Asci with varying number of spores, 

usually numerous 1. Hemiascomycetes, p. 118. 

Asci with definite number of spores 

> Asci separate or scattered 2. Protoascomycetes, p. 119. 

Asci approximate, usually forming a 

hymenium 3. Euascomycetes, p. 123. 



118 THE FUNGI WHICH CAUSE PLANT DISEASE 



Hemiascomycetes (p. 117) 

There is a single order, the Protomycetales, which contains about 
twenty-five species. Mycehum filamentous, branched, septate; 
conidia present; asci sporangia-like, containing numerous spores, 
terminal, naked or covered with a hyphal felt; in some species 
known to originate from the fertilization of an oogonium. 

Protomycetales 

Key to Families of Protomycetales 

Asci naked 

Asci long, tubular 1. Ascoideaceae. 

Asci elliptic or globular 2. Protomycetaceae, p. 118. 

Asci more or less covered by hyphse 3. Monascaceae. 

Of these families the first is found in slime flux; the last is sap- 
rophytic. 

Protomycetaceae 

Mycelium prominent; asci intercalary or terminal, large, de- 
velopment arrested before spores are formed; a process which is 
completed only after a period of rest. 

Key to Genera of Protomycetaceae 

Parasitic, intercellular in living plants 1. Protomyces, p. 118. 

Saprophytic, building hemispheric sporing 

masses 2. Endogone. 

Protomyces linger 

Asci thick walled; after a long period of rest forming a large 
mass of elliptic spores which conjugate in pairs, then germinate 
immediately by a germ tube. 

This genus is sometimes placed with the Phy corny cetes.^* 



THE FUNGI WHICH CAUSE PLANT DISEASE 



119 



P. macrosporus Ung. 

Asci globose to elliptic, 40-80 x 35-60 m; membrane yellowish, 
up to 5 M in thickness, contents colorless; spores elongate-ellipsoid, 
2-3 X 1 At. 

It produces small galls, which are at first watery looking, then 




Fig. 81. — Protomyces. .-1, mycelium and 
young ascus; E, ascus with mature spores. 



After De Bary. 



brown, upon the leaves and stems of various economic and non- 
economic Umbelliferae. 

P. pachydermus Thiim. affects carrots and dandelions. P. 
rhizobius Trail, grows on Poa annua in Scotland. Several other 
species are found on wild plants. 



Subclass Protoascomycetes (p. 117) 

There is a single order, the Saccharomycetales, with about 
seventy species. 

Mycelium often undeveloped ; asci isolated or formed at different 
points on the mycelium, mainly 4-spored; spores unicellular; 
asexual reproduction by gemmation or by conidia. 



120 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Key to Families of Saccharomycetales 



Vegetative cells single or loosely 
attached in irregular colonies, 
mycelium not usually developed, 
asci isolated, not differentiated 
from vegetative cells 

Vegetative cells forming a mycelium, 
asci terminal, or intercalary, 
differentiated from mycelium. . 



1. Saccharomycetaceae, p. 120. 



2. Endomycetaceae, p. 122. 



The first family, the yeasts, to vi^hich belong the majority of the 
species of the order, is of prime importance in fermentation. A 




Fig. 82. — Yeast plant-bodies, showing 
budding and sporulation. After 
Coulter and Rees. 



few species are known to cause animal diseases; others are found 
associated with the slime fluxes. 



Saccharomycetaceae 

Vegetative cells separate or few together, never truly filamen- 
tous, propagating by buds; asci globose to elliptic, 1 to 8-spored; 
growing typically in sugary or starchy materials. 



THE FUNGI WHICH CAUSE PLANT DISEASE 121 



Key to Genera of Saccharomycetaceae 

Vegetative cells globose, ovoid, pyriform, etc. 
Vegetative cells increasing by budding; 
asci typically 3 to 4 spored. 
Spores globose or ovoid. 

Spores upon germination forming 
typical yeast cells. 
Ascus formation preceded by the 

conjugation of like gametes. . 1. Zygosaccharomyces. 
Ascus formation not preceded by 
the conjugation of gametes. 

Spore membrane single 2. Saccharomyces, p. 121. 

Spore membrane double 3. Saccharomycopsis. 

Spores upon germination forming a 

poorly developed promycelium. 4. Saccharomycodes. 
Spores pileiform or limoniform, costate 5. Willia. 
Spores hemispheric, angular or irregular 
in form, upon germination forming 

an extended promycelium 6. Pichia. 

Vegetative cells increasing by fission; asci 

8-spored 7. Schizosaccharomyces. 

Vegetative cells elongate, cylindric; spores 
filiform, 

Asci 1-spored 8. Monospora. 

Asci 8-spored 9. Nematospora, p. 122, 



Saccharomyces Meyen 

Vegetative cells globose, ellipsoid, ovate, pyriform, etc., repro- 
ducing by budding and remaining attached in short, simple or 
branched pseudo-mycelial groups, at length separating; asci 
globose, ellipsoid, or cylindric, 1 to 4-spored (typically 3 to 4- 
spored), single or in chains; spores globose to ellipsoid, continuous. 

Many species, chiefly saprophytes. 

S. croci Roze is described as the cause of a crocus disease.^ 

From sorghum plants suffering from blight a yeast was isolated 
by Radais.^ This when inoculated in pure culture into healthy 
plants produced the characteristic lesions and effects. 



122 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Nematospora Peglion (p. 121) 

Colonies (in culture) disciform; cells elongate; asci cylindric, 
8-spored; spores filiform, continuous, long-ciliate, hyaline, 

Monotypic. 

N. coryli Pegl.,^ the cause of malformation of the hazel nut in 
Italy, is a peculiar fungus with what appears to be asci contain- 
ing eight long slender flagellated spores. 

Endomycetaceae (p. 120) 

Mycelium usually well developed, often producing a luxuriant 
growth, multiseptate; asci borne singly on branches, or inter- 
calary, 4 to 8-spored; spores one-celled; conidia produced apically, 
unicellular. 

Key to Genera of Endomycetaceae 

Mycelium poorly developed, parasitic on 

Mucorales 1. Podocapsa. 

Mycelium well developed 
Asci formed after conjugation of a pair of 

spirally entwined branches 2. Eremascus. 

Asci formed asexually, produced termi- 
nally, rarely intercalary. 

Asci 4-spored 3. Endomyces, p. 122, 

Asci 8-spored 4. Oleina. 

Endomyces Rees 

Mycelium well developed, byssoid; asci 
borne singly on the ends of short lateral 
l)ranches, globose to pyriform, 4-spored, 
spores continuous. 

The members of this genus are of ques- 
tionable importance as parasites. Some 
//CS^^ are commonly found in sap exuding from 
^"aes'of'i'^n^Sres t^^e wounds" where they, together with 
later form in these, other fungi present, set up a fermentation 
the products of which prevent the wound 
from healing and result in injury. One species has been re- 
ported in America as an active parasite on apples. 





THE FUNGI WHICH CAUSE PLANT DISEASE 123 

E. mali Lewis ^ 

Mycelium well developed, multiseptate; conidia formed on 
short conidiophores or on the ends of short germ tubes, averag- 
ing 3 X 8 m; no yeast-like budding; asci usually 
on short lateral branches, 11-14 n in diameter; 
ascospores sphaeroidal, slightly elongate, 4.5 x 
5.5 fi with thickened places on the walls, brown 
when mature. Figs. 83, 84. ^J 'g^ _j^ ^^j. 

Lewis isolated the fungus from decayed spots Typical manner 

, , , , ,, T 1 i- 1 of bearing conidia 

on apples by plate cultures. Inoculations proved on agar. After 
that it is capable of causing a slow decay with- *^^^^" 
out the aid of other fungi. An extensive cultural study as well as 
a considerable cytological study was made. 

E. decipiens (Tul.) Rees is parasitic on Armillaria; E. parasitica 
Fayod on Tricholoma."' " 

Euascomycetes (p. 117) 

This is an extraordinarily large group comprising some 16,000 
species, with great variety of size, color and shape of plant body. 
Most of them are saprophytes, still many are parasites either in 
their ascigerous or their conidial stages of development. 

The twelve orders may be recognized by the following key. 



Key to Orders of Euascomycetes 

Asci approximate in an indefinite hyme- 

nium, no ascoma 1. Protodiscales, p. 125. 

Asci grouped in a definite ascoma 

Asci collected in a flattened, concave or 

closed ascoma, often bordered by a 

distinct layer 

Ascoma at maturity open and more or 

less cup-like. Discomycetes 

Ascoma open from the first, clavate or 

convex, pitted, or gyrose 2. Helvellales, p. 130, 

Ascoma at first closed, opening early, 
without special covering, more 
or less fleshy 3. Pezizales, p. 133. 



124 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Ascoma opening tardily, enclosed by 
a tough covering which becomes 
torn open at the maturity of the 
spores 
Ascoma roundish, opening by stel- 
late or radiating fissures 4. Phacidiales, p. 154. 

Ascoma elongate, opening by a 

longitudinal fissure 5. Hysteriales, p. 159. 

Ascoma at maturity closed and tuber- 
like, subterranean, 6. Tuberales. 

Asci collected in a cj'lindric or globose 

perithecium 

Perithecia sessile, solitary and free, or 

united and embedded in a stroma 

Asci arranged at different levels in 

the perithecium 7. Aspergillales, p. 164. 

Asci arising from a common level 

Mycelium superficial, perithecia 

scattered, globose and without 

apparent ostiole, or flattened 

and ostiolate 8. Perisporiales, p. 170. 

Mycelium nearly superficial, peri- 
thecia ostiolate 
Perithecia and stroma (if pres- 
ent) fleshy or membranous, 

bright colored 9. Hypocreales, p. 195. 

Perithecia and stroma (if pres- 
ent) hardened, rarely mem- 
branous, dark colored 
Wall of perithecia scarcely 
distinguishable from the 

stroma 10. Dothidiales, p. 215. 

Perithecia with distinct wall, 
free or embedded in the 

stroma 11. Sphaeriales, p. 221. 

Perithecium borne on a short pedicel; 
microscopic fungi parasitic on 
insects 12. Laboulbeniales. 



Of these all contain plant parasites with two exceptions; the 
Tuberales, which bear underground tuber-like ascocarps, some of 



THE FUNGI WHICH CAUSE PLANT DISEASE 



125 



these prized as table delicacies, and the Laboulbeniales, an order 
rich in species which are all parasitic upon insects. 

Protodiscales (p. 123) 

The 4-8 to many-spored asci form a flat palisade-like hymenium 
which arises directly from the mycelium; paraphyses none; spores, 
one-celled, elliptical or round. 

Key to Families of Protodiscales 

Parasitic 1. Exoascaceae, p. 125. 

Saprophytic 2. Ascocorticiaceae. 

Of these families the second contains only one genus and two 
species found in bark. The first family is aggressively parasitic. 



Exoascaceae 



8-10. 292, 327 



This is the most simple of the parasitic Ascomycetes, definitely 
recognizable as such, and is comparable with the Exobasidiales 
among the Basidiomycetes. All the 
species are parasitic and many of 
them very injurious. The mycelium, 
which can be distinguished from 
that of other fungi by its cells of 
very irregular size and shape, wan- 
ders between the host cells (intra- 
cellular in one species), or is some- 
times limited to the region just Fig. 85.-Exoascus showing myce- 
below the cuticle. The asci develop Hum and asci. After Atkinson. 

in a palisade form on a mycelial network under the epidermis, or 
the cuticle, or on the ends of hyphse arising from below the epi- 
dermal cells. They are exposed by the rupture of the cuticle or 
epidermis and contain four to eight hyaline, oval, one-celled 
spores. These by budding, while still in the ascus, may pro- 
duce numerous secondary spores, conidia, which give the im- 
pression of a many-spored ascus. The ascospores also bud freely 
in nutritive solutions. The primary-ascus-nucleus arises from 




128 



THE FUNGI WHICH CAUSE PLANT DISEASE 






fusion of two nuclei as is general among the Ascomycetes. The 
spore-nuclei arise by repeated mitoses of the primary nucleus. 

Affected leaves, fruit and twigs become swollen and much dis- 
torted; wrinkled, curled, arched, puckered. In woody twigs the 

mycelium often induces 
unnatural, profuse, 
tufted branching result- 
ing in "witches brooms" 
though such structures 
often arise from irrita- 
tion due to other causes. 
Many attempts have 
TT cp T u • x. ■ -^ ■ ^.u been made to arrange the 

fiG. 8b. — 1 aphrina showing mitoses in the young _ _ ° 

ascus leading to the development of spore- species in natural genera; 

nuclei. After Ikeno. , , , , 

some based on the num- 
ber of ascospores, ' others largely on the biologic grounds of an- 
nual or perennial mycelium.^ Giesenhagen ^^ whose classification 
is followed here, recognizes two genera, Exoascus being merged 
into Taphrina. 

Key to Genera of Ezoascaceae 

Asci cylindric, clavate or abbreviate-cylin- 

dric, produced above the epidermis of 

the host 1. Taphrina, p. 126. 

Asci saccate, in epidermis 2. Magnusiella. 





Taphrina Fries 

Mycelium annual or perennial; asci 4 to 8-spored, or by germina- 
tion of the ascospores, multispored, borne on the surface of blisters 
and other hypertrophied areas, cylindric to clavate, or a modifica- 
tion thereof. Of this genus Giesenhagen ^^ recognizes four series 
of species which are arranged in three subgenera. 



Subgenus 1. Taphrinopsis, — one series (Filicina) 

The asci are slender clavate, narrowed at each end, rounded 
above, broadest in the upper fourth. Parasitic on ferns. None of 
the five species is of economic importance. 



THE FUNGI WHICH CAUSE PLANT DISEASE 127 



Subgenus. 2. Eutaphrina, — one series (Betula) 

Asci broadly cylindric, rarely contracted at the base or from 
the middle down, truncate above and sometimes in-sunken. On 
Amentacese, chiefly Betula, Alnus, Ostrya, Carpinus, Quercus, 
Populus. Of the twenty-four species of this series but few are 
of importance. 

T. coerulescens (D. & M.) Tul.^^ Annual, producing blisters 
on the leaves of oak, the sporing surface bluish; asci elongate, 
broadl}^ cylindric, 55-78 x 18-24 /x; spores breaking up into 
conidia. 

On various species of Quercus in Europe and America. 

T. ulmi (Fcl.) Joh., on the elm; T. aurea (Pers.) Fries on the 
leaves of Populus and T. johonsonii Sad. on the fertile aments of 
the aspen are among the more important remaining species of the 
series. 

Subgenus 3. Exoascus, — two series 

Asci clavate, normally cylindric or more or less abbreviated. 

(1) Prunus series on Rosacese. Asci slender, clavate, narrowed 
below, broadest in their upper fourth, varying through all inter- 
mediate forms to narrowly cylindric. 

(2) iEsculus series, on Sapindacae, Anacardiacese, etc. — Asci 
broadly cylindric, short, rounded or truncate. 

The more important economic species of the genus belong to 
the Prunus series. 

T. deformans (Fcl.) Tul.^- '-' '^ 

The irregular vegetative mycelium devoid of haustoria grows 
in the leaf parenchyma and petiole and in the cortex of branches. 
A distributive mycelium lies close beneath the epidermal cells of 
twigs and in the pith and extends some distance through the twig. 
Fig. 87. Branches arise from the vegetative mycelium, penetrate 
between the epidermal cells to the cuticle and then branch freely 
to form a network of short distended cells beneath the cuticle. 
This is the hymenium, a layer of ascogenous cells. These cells 
elongate perpendicularly to the host's surface, Fig. 85, rupture 
the cuticle, and form a plush-like layer. The protoplasmic con- 



128 



THE FUNGI WHICH CAUSE PLAxNT DISEASE 



tents crowds toward the tips of these cells and a basal septum cuts 
off the ascus proper from the stalk cell, Fig. 88. The spores then 
form within the ascus. The ascospores may bud either before 

or after extrusion 
from the ascus, pro- 
ducing conidia, which 
may themselves bud 
indefinitely, producing 
secondary, tertiary, 
etc., crops. In this 
condition the conidia 
strongly resemble 
yeast cells. On the 
host plant ascospores 
germinate by germ 
tubes, which are ca- 
p a b 1 e of infecting 
proper hosts. No 
success has rewarded 
attempts to secure 
germ tubes from co- 
nidia. Leaf infection 
is chiefly external; 
rarely internal from 
mycelium perennating 
in the twigs. It oc- 
curs when the leaf is 
very young. Infected 
leaves are thickened 
and broadened and 
the tissues are stiff 
and coriaceous. The 
palisade cells increase in size and .number and lose their chloro- 
phyll. Blistering and reddening of the leaves follows. 

Asci clavate, 25-40 x 8-11 ^; spores 8, subglobose or oval, 
3-4 IX. On the peach in Europe, North America, China, Japan, 
Algeria and South Africa. 

T. pruni (Fcl.) Tul.^' ^^ j^. f^^nd in Europe and North America 







Fiu. 87. — T. deformans 5, distributive hj'pha, 
1, vegetative hyphse; 9, sponferous hyphae. After 
Pierce. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



129 



on plum and wild cherry, causing "plum pockets." The ovary is 
the seat of attack. The mycelium after bud infection pervades 
the mesocarp which hypertrophies and alone produces a much 
enlarged fruit, usually with entire sacrifice of the other fruit parts. 
Asci are formed over the diseased surface much as in the last 
species. The mycelium is perennial in the bast and grows out into 
the new shoots and 
buds each spring. In- 
fection also reaches 
other shoots and trees 
by means of the spores. 

Ascus elongate-cylin- 
dric, 30-60 x 8-15 tx; 
spores 8, globose 4-5 ix. 
Perennial. 

T.cerasi(Fcl.)Sad.8'i^ 
produces the witches 
broom effect upon culti- 
vated and wild cherries. 
It is common in Eu- 
rope, rare in America. 
Perennial ; asci clavate 
30-50 X 7-10 m; spores 
8, forming conidia in 
the ascus, oval, 6-9 x 
5-7 II. 

On Prunus avium, P. cerasus, etc. in North America and 
Europe. 

T. mirabilis (Atk.) Gies.^' ^^ grows on leaf buds and twigs of 
Prunus angustifolia, P. hortulana, P. americana in North America. 

Perennial ; sporing on the fruits and tips of branches of the host ; 
asci subcylindric, blunt above, 25-45 x 8-10 /x; spores 8, ovate. 
, T. longipes (Atk.) Gies. is on Prunus americana in North 
America, causing plum pockets.^ 

Perennial; sporing on young fruits; asci cylindric, truncate or 
not, 30-40 X 7-10 ix; spores 8, globose or ovate, 3-4 ju. 

T. rhizipes (Atk.) Gies. Known only in North America, caus- 
ing pockets on Japanese plums ; ^ probably of wider distribution. 




T^-CTl 



Fig. 88. — T. deformans. Young and old asci. 
After Pierce. 



130 THE FUNGI WHICH CAUSE PLANT DISEASE 

Perennial; asci cylindric, or club-shaped, 30-40 x 8-10 n, 
appearing to have basal rhizoids; spores 8, globose. 

T. communis (Sad.) Gies.^ Perennial in branches; sporing on 
immature fruits; asci clavate, 24-45 x 6-10 ix; spores 8, elliptic, 
5 X 3-4 n, often producing conidia. 

On Prunus americana, P. maritima, P. nigra, and P. pmnila, in 
North America. 

T. institiae (Sad.) Joh. Forming witches brooms on Prunus 
institia, P. domestica, and P. pennsylvanica in Europe and 
America.^ 

Perennial; sporing on the under side of the leaf; asci clavate to 
cylindric, 25-30 x 8-10 jn; spores 8, not rarely producing conidia, 
globose, 3.5 jjl. 

T. decipiens (Atk.) Gies. On Prunus americana in North 
America.^ 

Perennial; sporing on under surfaces of leaves; asci irregularly 
clavate, often almost cylindric, 20-40 x 10 /i; spores breaking up 
into conidia. 

T. buUata (Fcl.) Tul. On pear and Japanese quince. 

Annual; asci clavate, 36-40 x 8-9 /i; spores 8, often forming 
conidia, globose, about 5 jx. 

T. farlowii (Sad.) Gies.^ is found on Prunus serotina in America; 
T. minor Sad. on leaves of Prunus chamaecerasus and P. cerasus, 
in Germany and England. It has recently caused considerable 
damage in South England. 

T. bassei Fab. causes witches broom of cacao in Kamerun. 

T. rostrupiana (Sad.) Gies. is on Prunus spinosa; 

T. crataegi (Fcl.) Sad. on Crataegus oxycantha. 

T. maculans Butler is reported on Tumeric and Zinzibar by 
Butler.-^^ T. theobromae Ritzema Bos. is reported as injurious to 
the cacao tree. 

Many other species of Taphrina of minor importance occur upon 
alder, poplar (Populus), Carpinus, birch, elm, maple, hawthorn, 
oak and numerous other hosts. 

Helvellales (p. 123) 

Ascoma fleshy, separable into a definite hymenium of asci and 
paraphyses and a stroma which is usually large and stalk-like; 



THE FUNGI WHICH CAUSE PLANT DISEASE 



131 



fertile portion more or less cap-like; hymenium free from the first 
or covered with a thin, evanescent veil; '^ asci cylindric, opening 
by an apical pore; spores ellipsoid, colorless or light yellow, smooth, 
or in one genus echinulate. 

Key to Families of Helvellales 

Ascocarp stalked 

Fertile portion clavatc or capitate; asci 

opening by an irregular slit 1. Geoglossaceae, p. 131. 

Fertile portion pileate; asci opening by a lid. 2. Helvellaceae. 
Ascocarp sessile 3. Rhizinaceae, p. 132. 

The majority of the species of this order are saprophytes, the 
only parasites being of the first and third families. Of the second 
family many of the species are edible and some are very large. 

Geoglossaceae 

Key to Tribes and Genera of Geoglossaceae 

Ascoma clavate or spatulate, ascigerous 
portion usually more or less com- 
pressed, rarely subglobose . . . . Tribe I. Geoglosseae. 
Ascoma clavate, fertile portion at most 
only slightly decurrent 
Spores small, elliptic, cylindric or 
fusiform, continuous ; plants 

bright colored 1. Mitrula, p. 132. 

Spores long, elliptic to cylindric, 3 to 
many-septate at maturity 

Hymenium bright colored 2. Microglossum. 

Hj^menium black or blackish 

Spores hyaline 3. Corynetes. 

Spores brown 4. Geoglossum. 

Ascoma spatulate or fan-shaped, as- 
cigerous portion decurrent on the stipe 
Ascigerous only on one side of the 

stem 5. Hemiglossum. 

Ascigerous on both sides the stem 

Spores globose 6. Neolecta. 

Spores elongate 7. Spathularia. 

Ascoma stalked, capitate or pileate, in one 

genus sessile II. Cudonieae. 



132 



THE FUNGI WHICH CAUSE PLANT DISEASE 




Fig. 89. — Mitrul 
sketch; F, asci 



Mitrula sclerotiorum Rost.^^ 
which causes a disease of alfalfa in 
Denmark is the only pathogen of 
the family. The infected plants die 
and later the roots and stems be- 
come filled with black sclerotia 
which lie dormant about a year. 

B, habit Upon resuming growth they be- 
After Schroter. , , ^■ ^ . ^ ^ 

come covered by light red eleva- 



tions, which bear small light red ascocarps. 

Rhizinaceae (p. 131) 
Key to Genera of Rhizinaceae 



Spores elliptic or spindle-shaped 

Without rhizoid-like structures 1. Psilopezia. 

With rhizoid-like structures 2. Rhizina, p. 132. 

Spores globose 3. Sphaerosoma. 

Only one genus, Rhizina, causes 
disease. 

Rhizina Fries with some eight 
species is recognized by its crust- 
formed, sessile, flat ascophore with 
root-like outgrowths from the lower 
side. Fig. 90. Asci cylindrical, 8- 
spored, opening by a lid; spores one- 
celled, hyaline; paraphyses many. It 
is often purely saprophytic, growing 
in burned-over spots in forests. 

R. inflata (Schaff) Quel.'^' ^* is 
counted as the cause of serious root 
diseases of forest trees, especially 
conifers, in Europe. The fungus also 
occurs in Asia and America. 

R. undulata causes death of fir seedlings. -^^ 




Fig. 90. — Rhizina inflata. B, asco- 
carp from below; C, asci and 
paraphyses. After Schroter and 
Tulasne. 



THE FUNGI WHICH CAUSE PLANT DISEASE 133 



Pezizales (p. 123) 

In this order unlike the last, the hymenium is at first enclosed 
but soon becomes exposed. The apothecia at maturity are typi- 
cally disc or saucer-shaped (Fig. 101) or sometimes deeper, as 
cup, beaker or pitcher-shaped. They vary from a size barely 
visible up to 8-10 cm. in diameter. Some are stalked, more often 
they are sessile. In consistency they vary from fleshy or even 
gelatinous to horny. Paraphyses are present and may unite over 
the asci to form a covering, the epithecium. The apothecium may 
be differentiated into two layers; the upper bearing the asci is the 
hypothecium, the lower the peridium. In some cases sclerotia 
are formed. Many species possess conidiospores as well as asco- 
spores, borne either on hyphae or in pycnidia. The great majority 
are saprophytes, a few are parasitic. There are some three thou- 
sand species. 

Key to Families of Pezizales 

No lichenoid thallus and no algal cells 
Ascocarps free, solitary or cespitose 
Ascocarps fleshy or waxy, rarely gelati- 
nous; ends of paraphyses free 
Peridium and hj^pothecium without 
distinct lines of junction 
Ascoma open from the beginning, 
convex; peridium wanting or 

poorly developed 1. Pyronemaceae. 

Ascoma concave at first; a fleshy 
peridium present. 
» Asci forming a uniform stratum, 

at maturity not projecting. 2. Pezizaceae. 
Asci projecting from the ascoma 

at maturity 3. Ascobolaceae. 

Peridium forming a more or less dif- 
ferentiated membrane. 
Peridium of elongate, parallel 
pseudo-parenchymatous, hya- 
line, thin-walled cells 4. Helotiaceae, p. 134. 



134 THE FUNGI WHICH CAUSE PLANT DISEASE 

Peridium firm, of roundish or angu- 
lar, pesudo-parenchymatous, 

mostly dark, thick-walled cells 5. MoUisiacese, p. 146. 
Ascocarps leathery, horny or cartilagi- 
nous ; ends of the paraphyses united 
into an epithecium 
Peridium wanting or poorly devel- 
oped 6. Celidiaceae. 

Peridium well developed, mostly 
leathery or horny 
Ascccarps free from the beginning, 
dish or plate-shaped, never en- 
closed by a membrane 7. Patellariacese. 

Ascocarps at first embedded in a 
matrix, then erumpent, urceo- 
late or cup-shaped, at first en- 
closed in a membrane which 

disappears later 8. CenangiaceaD, p. 150. 

Ascocarps borne on a highly developed 
stringy or globoid stroma 
Ascocarps at the ends of the branches 

of a cord-like stroma 9. Cordieritidaceae. 

Ascocarps embedded in the upper por- 
tion of a globoid stroma 10. Cyttariaceae. 

Lichenoid thallus more or less prominent, 
algal cells typically present, asci disap- 
pearing early, disk with a mazsedium. . 11. Caliciaceae, p. 153. 

The Pyronemacese, Peziacese, and Ascobolacese are pure sapro- 
phytes on organic matter in the ground or on rotting wood. The 
Patellariacese are largely, and the Celidiaceae are nearly all, para- 
sitic on lichens. The Cordieritidaceae of four species, possessing 
a stony stroma, are unimportant. The Cyttariacese, of one genus, 
and some six species, are limited to the southern hemisphere where 
they grow on branches of the beech. 

Helotiaceae (p. 133) 

In members of this family there is a distinctly differentiated 

peridium. The apothecia are usually fleshy or waxy, superficial, 

first closed, later opening; the paraphyses form no epithecium. 

Asci 8-spored. Spores round to thread-shaped, one to 8-celled, 



THE FUNGI WHICH CAUSE PLANT DISEASE 



135 



hyaline. Some of the genera are among the most serious of 
plant pathogens. About one thousand species. 

Key to Genera of Helotiaceae 

Ascocarps fleshy, fleshy-waxy, thick ormem- 
branous 
Ascocarps fleshy-waxy, brittle when fresh, 

leathery when dry I. Sarcoscypheae. 

Ascocarps felty hairy externally 1. Sarcoscypha. 

Ascocarps covered with bristle-like hairs 

externally 2. Pilocratera. 

Ascocarps naked 

Ascocarps springing from a sclero- 

tium 3. Sclerotinia, p. 136. 

Ascocarps not springing from a 
sclerotium 
Spores 1-celled 

Substratum green 4. Chlorosplenium, p. 144. 

Substratum uncolored 5. Ciboria. 

Spores at length 2 to 4-celled .... 6. Rutstroemia. 
Ascocarps waxy, thick, tough or mem- 
branous 

Ascocarps externally hairy II. Trichopezizeae. 

Ascocarps resting on an extended 
arachnoid mycelium 

Spores 1-celled 7. Eriopeziza. 

Spores becoming several-celled. . . 8. Arachnopeziza. 
Ascocarps without arachnoid my- 
celium 

Spores globose 9. Lachnellula. 

Spores ellipsoid or elongate 

Disk surrounded by black hairs. 10. Desmazierella. 
Disk smooth 
Paraphyses obtuse at the apex 
Walls of ascoma delicate; 
spores mostly 1-celled, 
rarely 2-celled at ma- 
turity 11. Dasyscypha, p. 144. 

Walls of ascoma thick; 
spores 2-celled at ma- 
turity 12. Lachnella, p. 145. 



136. THE FUNGI WHICH CAUSE PLANT DISEASE 

Paraphyses lancet-shaped at 
apex 

Spores 1 -celled 13. Lachnum. 

Spores at length several- 
celled 14. Erinella. 

Ascocarps naked III. Helotieae. 

Spores globose 15. Pitya. 

Spores ellipsoid or fusiform 
Spores 1-celled 

Border of disk smooth 16. Hymenoscypha, p. 146. 

Border of disk toothed 17. Cyathicula. 

Spores at length 2 to 4-celled 
Ascocarps sessile, rarely com- 
pressed at base 18. Belonium. 

Ascocarps stalked, or at least 
compressed like a stalk 
Walls of ascoma waxy; stem 

short and dehcate 19. Belonioscypha. 

Walls of ascoma waxy, thick; 

stem thick 20. Helotium. 

Spores filiform 

Ascocarps sessile 21. Gorgoniceps. 

Ascocarps stalked 22. Pocillum. 

Ascocarps gelatinous gristly, horny when 

dry IV. Ombrophileae. 

Of these genera only the five given below have parasitic represen- 
tatives of economic importance, while only one to two others are 
parasitic. The rest grow as saprophytes on rotting wood and 
organic debris in the soil. 

Sclerotinia Fuckel (p. 135) 

This genus contains several very important pathogens, some 
of them preying upon a wide range of hosts and causing great loss. 
A striking feature of the genus is the sclerotium which is black and 
borne within the host tissue or upon its surface. From the sclerotia 
after a more or less protracted period the apothecia develop. These 
are disc-shaped and stalked. The asci are 8-spored ; spores elliptical 
or fusiform, unicellular, hyaline, straight or curved. Some species 



THE FUNGI WHICH CAUSE PLANT DISEASE 



137 




Fig. 91. — S. urnula, 
moniliform conidia 
with disjunctors. 
After Woronin. 



possess Botrytis forms (see pp. 141 and 578), others Monilia (see 

pp. 139 and 558) forms of conidial fructification. In addition to 

these there may be gonidia, which appear to be 

degenerate, f unctionless conidia. In some species 

there is no known spore form except that in the 

ascus. 

S. ledi Now. is of especial interest as the one 
fungus outside of the Uredinales that exhibits 
heteroecism.^^" 

Many forms found upon separate hosts and 
presenting shght differences under the micro- 
scope, often even no microscopic differences, 
have been named as separate species. Only 
long careful culture studies and inoculation ex- 
periments will determine which of these species 
are valid, where more segregation, where more 
aggregation is needed. 

The mere association of Botrytis or Monilia 
conidial forms with Sclerotinia, in the same host, 
has repeatedly led to the assumption that such forms were genetic- 
ally connected. Such assumptions are not warranted. Only the most 
careful study and most complete evidence justify such conclusions. 

The genus contains some fifty species which are divided into two 
subgenera; Stromatinia Boud., forming sclerotia in the fruits of 
the host; Eusclerotinia Rehm forming sclerotia in or on stems 
and leaves of the host. 

When conidia are known those of Stromatinia are of the Monilia 
tj'pe and those of Eusclerotinia of the Botrytis type. Each group 
contains important economic species. 

S. fructigena, S. cinerea and S. laxa.'-°' -^' -^' -^i-^ss 

These forms are perpetuated chiefly by their conidia. The 
ascus-forms are much less often seen. 

When the conidia. fall upon the peach, the mycelium develops 
and penetrates even the sound skin; then rapidly induces a brown 
rot. The mycelium within the tissue is septate, much branched, 
and light brown in color. It soon proceeds to form a subepidermal 
layer and from this the hyphie arise in dusty tufts of Monilia-form 
conidiophores and conidia (Fig. 92) . The earlier conidia are thin- 



138 



THE FUNGI WHICH CAUSE PLANT DISEASE 



walled and short lived, the later ones thicker walled and more 
enduring. 

After some weeks these tufts cease forming and disappear. The 
mycelium within the fruit persists, turns olivaceous and forms 
large irregular sclerotioid masses which on the following spring 
may produce fresh conidia. 

These sclerotioid (mummified) fruits under suitable conditions 





Fig. 92. — Sclerotinia on plum, a, section showing a spore pustule and chains 
of conidia; b, part of a spore-chain; c, spores germinating; d, a mummy 
plum and ascophores; e, an ascophore; /, ascus; g, mature spores. After 
Longyear. 

in nature, usually at blossom time of the host, can also produce 
apothecia, a fact first demonstrated by Norton. ^^ 

These apothecia develop in large numbers from old fruits half 
buried in soil, and send forth ascospores to aid in infection. The 
ascospores germinate readily in water and it was proved by Norton 
that they give rise to a mycelium which produces the characteristic 
Monilia. Inoculation of ascospores on fruit and leaves also gave 
positive results in two or three days. The flowers, and through 
them the twigs, are also invaded by the mycelium which seeks 
chiefly the cambium and bast. Shot-hole effect is produced on 
leaves of peach and cherry (Whetzel ^^). Infection is frequently 
through minute wounds.^* 



THE FUNGI WHICH CAUSE PLANT DISEASE 



139 




Fig. 93.— S. fuckeli- 
ana, attachment 
organ. After Ist- 
vanffi. 



On the apple the fungus shows two different modes of develop- 
ment. In some cases the mycehum accumulates under the epider- 
mis without producing spores, becomes dark colored and also 
causes a darkening of the contents of the host cells, which results 
in a black spot giving rise to the name black 
rot. In other cases ^^ the mycelium produces a 
brown rot and abundant conidial tufts, ar- 
ranged in concentric circles around the point 
of infection. 

The form on pomaceous fruits has long been 
regarded as identical with that on stone fruits; 
but recently, at least in Europe, they have been 
distinguished on cultural and morphological 
grounds * (see also^^'^'^), as separate species, 
the most distinctive character perhaps being 
the color of the mass of conidia. In a similar 
way S. laxa Ad & Ruhl. is set aside as a distinct species infecting 
only apricots. ^-^ 

American mycologists are inclined to doubt the distinctness of 
the species on drupes and pomes in this country. 
S. fructigena (Pers.) Schr. 
Apothecia from sclerotia produced either 
in or on mummied fruits, 0.5-3 cm. high, 
stem dark brown, disk lighter, 5-8 or even 
15 mm. in diameter; asci 125-215 x 7-10 /z; 
spores ellipsoidal, 10-15 x 5-8 /i. 

Conidia (=Monilia fructigena Pers.). Co- 
nidiophores covering the fruits of the host 
with a dense mold-like growth of light 
brownish-yellow or ochraceous color; spores 
averaging 20.9 x 12.1 /x. On stone and 
pome fruits, especially the latter. 
S. cinerea (Bon.) Wor. 
Apothecia and asci similar to those of 
S. fructigena, Conidia (=Momlia cinerea 
Bon.). Conidiophores covering the fruits 
with a dense grayish mold-like growth; spores averaging 12.1 x 
8.8 fjL. On stone and pome fruits, especially the former. 




Fig. 94. — -Typical conid- 
iophore and conidia 
of the Botrytis-form 
of S. fuckeliana. Af- 
ter Smith. 



140 THE FUNGI WHICH CAUSE PLANT DISEASE 

S. linhartiana P. & D.^^ is reported on quince in France. S. 

mespili Schell on medlar. S. seaveri, Rehm., conidia = Monilia 

seaveri, is on Prunus serotina.^^^ 

S. padi Wor. is found on Prunus padus and Castanea.^^ 

It possesses a Monilia-form conidial stage with typical dis- 

junctors, i. e., spindle-shaped cellulose bodies between the conidia, 

which easily break across to facilitate the separation of the conidia. 




Fig. 95. — S. libertiana. Sclerotia produced in artificial cul- 
ture. After Stevens and Hall. 

S. oxycocci Wor. is found on cranberry. It is unique in that 
half of the spores in each ascus are larger than the others. The 
conidial stage is a Monilia. 

S. fuckeUana (De Bary) Fcl.'-^ 

Apothecia in clusters of 2-3 from sclerotia in the leaves, rarely 
in the fruits, of the host, yellowish-brown, 0.5-4 /i across, stem 
slender; ascospores 10-11 x 6-7 /x. 

Conidia (=Botrytis cinerea Pers., B. vulgaris Fr.). Conidio- 
phores simple or branched, forming dense gray tufts; conidia sub- 
globose, usually minutely apiculate, almost hyaline, 10-12 n. 
Fig. 94. 



THE FUNGI WHICH CAUSE PLANT DISEASE 141 

It causes a rot of the grape, much dreaded in Europe, attacking 
leaves, fruit and stem. The fungus can persist long as a sapro- 
phyte in the conidial condition. Sclerotia are borne within the 
affected tissues. On germination they may either produce the 
conidia directly or form apothecia. Both ascospores and conidia 
are capable of infecting the grape but infection is much more 
certain from a vigorous mycelium (see S. libertiana, p. 142). 

Attachment organs, c. f. Fig. 93, which consist of close branch- 
clusters and seem to be induced by contact of a mycelial tip with 
any hard substance are present in abundance. Both toxins and 
digestive enzymes are produced.-^' ^^ 

Botrytis douglasii on pine is perhaps identical with the conidial 
form of the last fungus (see p. 140) as may also be the Botrytis of 
Ward's Lily Disease; ^° the Botrytis causing disease of goose- 
berries ^^ and many others that have been named as distinct 
species of Botrytis. 

S. galanthina Ludwig, close kin to S. fuckeliana, attacks snow- 
drops. S. rhododendri Fisch. occurs on Rhododendron. 

The former of these two is supposed to be the ascigerous form 
of Botrytis galanthina Berk. & Br. but no conclusive proof has 
been adduced. 

S. libertiana Fcl.^- 

Sclerotia from a few millimeters up to 3 cm. in length, black; 
apothecia scattered, pale, 4-8 mm. or more broad, stem slender; 
asci cylindric, 130-135 x 8-10 ^t, apically 
very slightly bluish; spores ellipsoid, 
usually minutely guttulate, 9-13 x 
4-6.5 fx; paraphyses clavate. 

This fungus affects numerous hosts. 
Among the most important on which it 
causes serious disease are lettuce, ^^' ^^* ^^' ^^ 
ginseng,^^ cucumber,^^ carrot, potato, Fig. 96.— S. lii.citiana. 
parsley, hemp, rape, various bulbs, zinnia, Ifte^sfeven^'* and Hall"''' 
petunia, etc. The white mycelium is 

found superficially and within the host, especially at places 
where moisture is retained, as between leaves, at leaf axils, etc., 
also within plant cavities. Microscopically it consists of long 
cells branching in a rather characteristic way. Fig. 97. Within 




142 



THE FUNGI WHICH CAUSE PLANT DISEASE 




Fig. 97. — Mycelium showing septation and 
branching. After Stevens and Hall. 



the host's tissue the hyphal threads are thicker, richer in proto- 
plasm, more septate, and much more branched and crooked 
than outside of the host. Aerial hyphal filaments when they 
touch a solid repeatedly branch in close compact fashion form- 
ing the attachment organs. 

At the exhaustion of the food supply and the consequent term- 
ination of the vegetative period the mycelium becomes very dense 
in spots and within these clumps of mycelium the sclerotium 
forms; at first white, later pink, finally smooth and black (Fig. 95). 
They are often found in the leaf axils (lettuce), in the pith of 

stems (carrot), etc. Under 
some conditions, as on un- 
suitable nutrient media, 
gonidia are produced. 

The sclerotia can ger- 
minate at once or remain 
dormant for one, perhaps 
several years. On ger- 
mination they send forth 
from 1 to 35 ^"^ negatively geotropic sprouts which grow to the 
soil surface unless that be more than about 5 cm. distant. On 
reaching the light the apex of the sprout begins to thicken and 
soon develops its apothecium; at first inverted- 
conidial, soon flat, and finally somewhat revo- 
lute. Changes in atmospheric humidity cause 
the discharge of ascospores in white clouds. 

The ascospores germinate readily but the re- 
sulting mycelium is of such small vigor that it 
is incapable of parasitism. If the ascospore 
germinates where it can maintain a saprophytic Fig. 98.— S. liber- 
life until a vigorous mycelium is developed then paraphyses^.'^^ After 
the mycelium may become parasitic. Stevens and Hall. 

Both ascospores and mycelium are comparatively short-lived. 
The mycelium can migrate but a short distance over soil. No 
form of conidia except the apparently functionless gonidia is 
produced. The fungus may be cultivated easily upon almost any 
medium, corn-meal-agar is especially suitable. 

It has been repeatedly claimed that this fungus possesses a 




THE FUNGI WHICH CAUSE PLANT DISEASE 



143 



Botrytis conidial stage l)iit the results of much careful work deny 
this.34' 40 

Recent tests by Westerdijk ^'^ indicate the absence of such 
biologic specialization in regard to hosts as 
is found in the Erysiphe and elsewhere. 

S. nicotianae Oud. & Kon.^^' "^^ parasitize;; 
the leaves and stems of tobacco. It is 
possibly identical with S. libertiana. 
S. trifoliorum Erik.^^"^^ 
In general this resembles S. libertiana 
with which it is by some regarded as iden- 
tical; sufficient evidence has, however, not 
been adduced to prove them the same. 
The sclerotia, varying in size from that of 
a mustard seed to a pea, are found in the de- 
cayed tissue, or as larger flat surface sclero- 
tia. No conidia except 
the functionless gonidia. 
Unknown on clover. 

S. bulborum (Wak.) 
Rehm "^^ which is very 
similar to S. trifoliorum 

and without known conidia grows on hyacinth, 
crocus, scilla and tulip. Cross infections be- 
tween hyacinth and clover have not, however, 
been successful and the species may be dis- 
tinct. A sterile form, Sclerotium tuliparum, 
found on the tulip may also belong here. 

S. tuberosa Fcl. is found on wild and culti- 
vated anemones. 

Several other species of the genus, among 
them S. alni Maul, S. betulae Wor., S. aucupa- 
riae Ludw, S. crategi Magn., are found on 
Ericacese, Betulacese, Rosacese, Graminese, etc., but they are not 
of sufficient economic importance to warrant further notice 
here. 





Fig. 99. — Cultures of .scle- 
rotinia from tobacco on 
potato agar, showing 
sclerotia. After Clinton. 



K 

Fig. 100.— C. serug- 
inosum. J, ascus; 
K, ascospores; L, 
conidia. After 
Rehm and Bre- 
feld. 



144 THE FUNGI WHICH CAUSE PLANT DISEASE 



Chlorosplenium Fries (p. 135) 

Ascoma mostly aggregated, small, stalked, smooth without, 
green; asci cylindric, 8-spored; spores elongate, 1-celled, guttulate, 
hyaline; paraphyses linear. 

The genus consists of some ten species only one of which is of 
interest hero. 

C. aeruginosum (Oed.) d Not. 

The apothecia and mycelium are verdigris-green as is also the 



Fig. 101. — D. wilkomii. A, natural size and single apothe- 
cium enlarged; B, an ascus. After Lindau. 

wood penetrated by it. The fungus appears to be mainly sapro- 
phytic but may be partially parasitic. Fig. 100. 

Dasyscypha Fries (p. 135) 

This is a genus of some one hundred fifty species, mostly sapro- 
phytic but sometimes parasitic on twigs. The apothecia are small, 
short-stalked or sessile, waxy or membranous, bright colored in the 
disk, with mostly simple hairs on the outside and margin. Asci 
cylindrical or clavate, 8-spored; spores ellipsoid or fusiform, 
hyaline, 1-celled, rarely 2-celled, sometimes guttulate; paraphyses 
blunt, needle-like. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



145 




D. willkommii Hart.''' causes a serious European larch disease 
and affects also the pine and fir. 

The stromata appear as yellowish-white pustules on the bark 
soon after its death. Here hyaline conidia are produced on the 
open surface or in cavities. Apothecia 2-5 mm. broad appear 
later. The ascospores can infect wounds: the conidia seem to be 
functionless. The myce- 
lium spreads through the 
sieve tubes, intercellular 
spaces, and xylem to the 
pith. 

Apothecia short-stalked, 
yellowish without, orange 
within; asci 120 x 9 fx; 
spores 18-25 x 5-6 n; 
paraphyses longer than 
the ascus. 

D. resinaria Rehm ''^ is 
a wound parasite much 
like the above in its ef- 
fects. It occurs chiefly on 
spruce and larch but sometimes also on pine, both in Europe 
and America. 

Ascophores upon cankers on branches and trunk of the host, 
very similar to those of the preceding species but with more evident 
stipe and paler disk; spores very minute, subglobose, 3 x 2-2.5 ju; 
conidia 2x1 ix. 

D. calyciformis (d Wild.) Rehm occurs on several conifers; 
D. subtilissima (Sacc.) on fir and larch; D. abietis Sacc. on Picea. 



Fig. 102. — Lachnella. F, habit sketch ; G, ascus 
and paraphyses. After Rehm. 



Lachnella Fries (p. 135) 

This is similar to the last genus but with the apothecia usually 
sessile and the spores usually 2-celled at maturity, and in two 
rows in the ascus. There are about forty species. 

L. pini Brun.^® injures pine twigs. The apothecia are brown 
outside; the disc reddish-yellow with a white margin. 

Ascoma short-stipitate, 5 mm. in diameter, pale brown; disk light 



146 



THE FUNGI WHICH CAUSE PLANT DISEASE 



orange-red with a pale margin; asci 109 x 8-9.5 fx; spores 19-20 x 
6.5-8.5 fx, hyaline. 

Hymenoscypha Fries (p. 136) 

This genus of over two hundred species is mainly saprophytic, 
one species only in its conidial stage being parasitic. 

Ascoma sessile or short-stipitate, usually 
smooth; asci cylindric to globoid, 8-spored; 
spores elliptic, blunt to pointed, hyaline; 
paraphyses filamentose, apically enlarged, 
hyaline. 

H. tumulenta P. & D.^° in its conidial 
stage as Endoconidium, affects rye grain 
causing it to shrivel and assume poisonous 
properties. The conidia are borne en- 
dogenously in the terminal branches of the 
hyphse and escape through an opening in 
the end of the branch. 




Fig. 103. — Hymenoscy- 
pha. J, habit sketch; 
K, ascus and paraphy- 
ses. After Rehm. 



MoUisiaceae (p. 134) 

Ascocarp free from the first or sunken in 
the substratum and later erumpent, at first 
more or less globose, becoming flattened; asci 8-spored, opening 
by a slit; spores hyaline, 1 to many-celled; paraphyses slender. 
Above four hundred species. 

Key to Genera of Mollisiaceae 

Ascocarp fleshy, waxy, rarely membranous. I. Mollisieae. 
Ascocarps not sunken in the substratum 
Ascocarps on a visible, often radiate 
mycelium 
Spores elongate, often fusiform, 

1-celled 1. Tapesia. 

Spores filiform, many-celled 2. Trichobelonium. 

Ascocarps not seated on a visible my- 
celium 
Spores 1-celled 

Spores spherical 3. Mollisiella. 

Spores elongate 4. MoUisia. 



THE FIINGI WHICH CAUSE PLANT DISEASE 147 

Spores becoming 2-celled 5. Niptera. 

Spores elongate filiform, -l-celled .... 6. Belonidium. 

Spores filiform many-celled 7. Belonopsis. 

Ascocarps at first smiken in the substra- 
tum, later erumpcnt 
Ascocarps bright colored, only slightly 
erumpent 
Spores ellispoid or elongate, rounded, 

1-celled 8. Pseudopeziza, p. 147. 

Spores becoming many-celled 9. Fabraea, p. 149. 

Ascocarps dark colored, at length 
strongly erumpent 
Spores ellipsoid or fusiform, 1-celled 
Ascocarps bristly externally and on 

the margin 10. Pirottaea. 

Ascocarps externally smooth, the 
margin at most merely shred- 
ded 11. Pyrenopeziza. 

Spores many-celled by transverse 

septa 12. Beloniella. 

Ascocarps gelatinous gristly, horny when 

dry 11. Callorieae. 

Of this large number of genera only two are important patho- 
gens, several of the others are parasitic on non-economic hosts 
while others are saprophytic chiefly on decaying woody parts. 

Pseudopeziza Fuckel 

The genus comprises some ten species, all parasitic on leaves, 
several of them upon economic plants causing serious disease. 
The very small apothecium develops subepidermally breaking 
through only at maturity, light colored; spores 1-celled, hyaline, 
in two ranks in the ascus; paraphyses somewhat stout, hyaline. 
Conidial forms are found in Gloeosporium, Colletotrichum and 
Marssonia. 

P. medicaginis (Lib.) Sacc.^^' ^" 

The epiphyllous apothecia are in the older leaf spots, subepider- 
mal at first but eventually breaking through. 

Apothecia saucer-shaped, light colored, fleshy; asci clavate; 



148 



THE FUNGI WHICH CAUSE PLANT DISEASE 




Fig. 104. — P. trifolii. Ascus and paraph- 
yses; germiuating spores. After Ches- 
ter. 



spores hyaline, 10-14 ^u long; paraphyses numerous, filiform. A 
Phyllosticta thought to be its conidial stage has been reported.^' 

On dead spots in leaves of alfalfa and black medick. 

P. trifolii (Bernh.) Fcl. 

This is closely related to, perhaps identical with, the last species. 
Sporonema (Sphseronsema) phacidioides Desm. is supposed to be 

\lj/f^ ^^ its conidial form. This co- 

^'' ^ nidial stage has not however, 

'm 9->, r-^, M /, ^^ been observed on alfalfa. 

Ascocarps mostly epiphyl- 
lous, on dead spots, averaging 
0.5 mm. broad, yellowish or 
brownish; spores elliptic 10- 
14 X 5-6 ix. 

Conidia in cup-shaped pyc- 
nidia which are numerous, small, light brown; disk cinnamon- 
colored; conidia ovoid-oblong, 5 /x, bi-guttulate. 

P. tracheiphila Miiller-Thurgau ^^ is found upon the grape in 
Europe. 

P. salicis (Tul.) Pot. occurs on Salix. Conidia ( =Gloeosporium 
salicis). 

P. ribis, Kleb.^^-^7 

Apothecia appear in the spring on dead leaves of the previous 
season; saucer-shaped, fleshy, somewhat 
stalked; asci clavate, spores hyaline, 
ovoid; paraphyses simple or branched, 
slightly clavate, rarely septate. 

Conidial phase (=Glceosporium ribis) 
on the leaves of the host forming an 
abundant amphigenous infection; acer- 
vuli stromatic; conidiospores commonly 
19 X 7 ju, varying from 12-24 x 5-9 /jl, 
escaping in gelatinous masses. 

On red and white currants less com- 
monly on black currants and gooseberries both in Europe and 
America. 

The ascigerous stage of this fungus was demonstrated by 
Klebahn "''^ in 1906 to be genetically connected with what had been 




Fig. 105.— p. ribis 
cium in section, 
bahn. 



Apothe- 
After Kle- 



THE FUNGI WHICH CAUSE PLANT DISEASE 149 

earlier known as Gloeosporium ribis (Lib.) Mont. & Desm. Old 
leaves bearing the latter fungus were wintered out-doors in filter 
paper and in the spring were found with this ascigerous stage. 
The ascospores were isolated, grown in pure culture and typical 
conidia were produced. The ascospores also infected the host 
leaves successfully producing there the typical Gloeosporium. 
The conidial stage is the only one ordinarily seen. The acervuli 
are subepidermal elevating the epidermis to form a pustule which 
eventually ruptures and allows the spores to escape as a gelatinous 
whitish or flesh-colored mass. The spores are curved and usually 
larger at one end than at the other. 

Fabraea Saccardo (p. 147) 

This is a genus of some ten species of small leaf parasites 
which much resemble Pseudopeziza but differ from it in its 2 to 
4-celled spores. 

F. maculata (Lev.) Atk.^^-^o 

The perfect stage is common on pear and quince leaves which 
have wintered naturally. When such leaves are wet the white 
8-spored asci may be seen 
crowding through the surface 
in small elliptical areas. The 
apothecium is paraphysate; the 
spores hyaline and 2-celled. 

Conidial form ( = Entomo- 
sporium maculatum) on leaves 
and fruits; acervuli, black, 
subepidermal, the epidermis 
breaking away to expose the p,^_ loe.— F. maculata. i, acervuius of 
spore mass; spores hyaline Aftir'soutSrth ^''''^'°"' ^' ^p"'"''^* 
18-20 X 12 /x, 4-cells in a 

cluster, the lateral cells smaller, depressed; stipe filiform 20 x 
0.75 n; the other cells with long setse. 

Atkinson ^^ proved the connection of the ascigerous with the 
conidial form by cultivating the conidia from the ascospores. The 
conidial form is very common and destructive on pear and quince 
leaves and fruit. The mycelium which abounds in the diseased 
spot is hyaline when young, dark when old. It collects to form a 




150 THE FUiNGI WHICH CAUSE PLANT DISEASE 

thin subcuticular stroma. On this the spores are produced on 
short erect conidiophores, Fig. 106; eventually the cuticle ruptures 
and the spores are shed. The spores germinate by a tube which 
arises from near the base of a bristle. 

F. mespili (Sor.) Atk. on medlar with the conidial form Entomo- 
sporium mespili (D. C.) Sacc. is perhaps identical with the above. 
There are only minor and uncertain differences in the conidial 
stage.^^ Sorauer by inoculation with conidiospores produced on 
pear typical spots which bore mature pustules after an interval of 
about a month. He referred the fungus to the genus, Stigmatea 
Fries. See p. 243. 

Cenangiaceae (p. 134) 

Ascoma at first buried, later erumpent, on a stroma, dark, with a 
rounded or elongate disk; asci 8-spored; spores long or filiform, 1 to 
many-celled, often muriform, hyaline or dark; paraphyses branched 
forming a complete epithecium. About two hundred fifty species. 

Key to Subfamilies and Genera of Cenangiaceae 

Ascocarps coriaceous, corneous or waxy 

when fresh I. Dermateae. 

Ascocarps without a stroma, at first im- 
mersed. 
Spores 1-celled 
Ascocarps externally bright colored, 

downy 1. Velutaria. 

Ascocarps externally dark 

Ascocarps smooth; spores hyaline. 2. Cenangium, p. 151. 
Ascocarps downy; spores colored. . 3. Schweinitzia. 
Spores 2 to 4-celled, elongate 
Spores hyaline 

Spores always 2-celled; ascocarp 

smooth 4. Cenangella. 

Spores 2 to 4-celled; ascocarps 

downy externally 5. Crumenula. 

Spores at length brown or black 

Disk elongate with a thick rim. . . 6. Tryblidiella. 
Disk rounded 

Rim thin; spores 2-celled 7. Pseudotryblidium. 

Rim involute; spores 4-celled. . 8. Rhytidopeziza. 



THE FUNGI WHICH CAUSE PLANT DISEASE 151 

Spores many-celled, filiform 9. Gordonia. 

Ascocarps springing from a more or less 
developed stroma 
Spores 8, not sprouting in the ascus. . . 10. Dermatea, p. 152. 
Spores sprouting in the asci which be- 
come filled with conidia 11. Tympanis. 

Ascocarps gelatinous when fresh II. Bulgarieae. 

Ascocarps sessile or stalked, with smooth, 
saucer-shaped disc 

Spores 1-celled, round 12. Pulparia. 

Spores 1-celled, elongate 
Ascocarps soft, gelatinous inside, ses- 
sile, thin 13. Bulgariella. 

Ascocarps soft, gelatinous, stalked, 

thick 14. Bulgaria, p. 152. 

Ascocarps watery gelatinous 15. Sarcosoma. 

Spores 2-celled 
Spores unequally 2-celled rounded 

at the ends 16. Paryphedria. 

Spores elongate, acute at the ends. . 17. Sorokina. 

Spores filiform 18. Holwaya. 

Spores muriform 19. Sarcomyces. 

Ascocarps with convolute tremelliform 
discs 

Spores 1-celled, hyaline 20. Haematomyces. 

Spores muriform, blackish 21. Haematomyxa. 

With few exceptions these genera are so far as known sapro- 
phytes though it is probable that further study will reveal some of 
them as weak parasites or possibly as destructive ones. 

Cenangium Fries (p. 150) 

Parasitic or saprophytic chiefly in bark, the apothecium de- 
veloping subepidermally and later breaking through to the surface ; 
sessile, light colored without, dark within; asci cylindric-globoid, 
8-spored; spores ellipsoid, 1 or rarely 2-celled, hyaline or brown, in 
one row; paraphyses colored. About seventy species. 

C. abietis (Pers.) Rehm.^^ has caused serious epidemics upon 
pine in Europe and America. 

Ascoma dark-brown, erumpent, clustered; spores ellipsoid, 
10-12 X 5-7 IX. 



152 



THE FUNGI WHICH CAUSE PLAxNT DISEASE 




Fig. 107. — Ceuangium, habit sketch, asci and 
paraphyses. After Tulasne. 



Conidia ( = Brunchorstia 
destuens Erikss.) in pyc- 
nidia which are partially 
embedded in the host, 
the smaller simple, the 
larger compound, 1-2 mm. 
in diam. ; spores 30-40 x 
3 ju, tapering-rounded at 
each end, 2 to 5-septate. 

A second conidial phase 
( = Dothichiza ferruginosa 



Sacc.) has simple spores. 

C. vitesia occurs in conidial form as Fuckelia on Ribes. 



In many 



Dermatea Fries (p. 151) 

A genus of over sixty .species some of them parasitic 
species conidia in pycnidia are known. 

Ascocarps scattered or clustered, stromate, sessile or not, 
black or brown; asci small, thick- 
walled, 8 or 4-spored; spores el- 
lipsoid or spindleform, 1-celled, 
becoming 4 to 6-celled, brown, 
2-ranked; paraphyses septate, api- 
cally enlarged and colored. 

D. carpinea (Pers.) Rchm. is 
a wound parasite on the horn- 
beam and beech; D. cinnamomea 
(Pers.) Rehm. on oaks; D. acerina 
Karst, on maple (Acer pseudo- 
platanus) ; all in Europe. 

D. prunastri (Pers.) Fr., with 
its conidial form Sphseronema spurium Fr. is found on Bark of 
various species of Prunus, in Europe and America. 

Bulgaria Fries (p. 151) 
The gelatinous apothecium is rather large and dark colored; 
asci 4 to 8-spored; spores 1-celled, elongate, brown. 
There is one species worthy of mention. 




Fig. 108.- 



A, h a 1) i t 



Dermatea. 
sketch; C, ascus and paraphyses. 
After Tulasne and Rehm. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



153 



B. polymorpha (Oed.) Wett."'-' ''^ is a common saprophyte on 
bark. It is said to sometimes become parasitic. Ascocarps black, 
stipitate; disk scarcely cupped, ranging up to 4 cm. in diameter 
although usually smaller. 



Caliciaceae (p. 134) 

Stroma more or less thalloid, with or 
without algal cells, often rudimentary and 
inconspicuous; ascoma more or less globoid, 
stipitate; the apex of the ascus dissolv- 
ing before the spores are matured, thus 
allowing the hyaline unripened spores to es- 
cape and mature afterwards. 

This small family (less than one hun- 
dred twenty-five species) contains the only 
lichens of phytopathological importance, un- 
less the foliose lichens which sometimes ap- Fig. io9. — C. 
pear on poorly kept fruit trees be consid- 2, a s c u s. 
ered. ^^''^^• 




/^ 



1 



pallida 
Root. 
After 



Key to the Genera of Caliciaceae 

Ascoma with a long stalk 

Spores spherical, or subspherical 

Spores colorless or only slightly colored. 1. Coniocybe, p. 153. 

Spores brown or brownish 2. Chaenotheca. 

Spores elongated, septate 

Spores elongate elliptic or egg-shaped, 

usually two-celled 3. Calicium. 

Spores elliptic to spindle-form, 4 to 

8-celled 4. Stenocybe, 

Ascoma short stalked 

Spores 2-celled 5. Acolium. 

Spores globose, 1-celled 6. Sphinetrina. 



Coniocybe pallida (Pers.) Fr. is generally distributed through- 
out Europe and America, commonly on the bark of various forest 
trees and upon the crown and roots of the grape. The parasitic 



154 THE FUNGI WHICH CAUSE PLANT DISEASE 

nature of the fungus is in doubt. The entire height of the as- 
cocarp is 2 mm.; head white, then grayish brown; asci cyUndric, 
8-spored; spore tinged with brown, 4-5 ix in diameter. The species 
as a pathogen is usually referred to as Rcesleria hypogsea Thiim 
& Pass, and given a place in the Geoglossaceae; but Durand ^* fol- 
lows Schroter in excluding the species from that family. Fig. 109. 

Phacidiales (p. 124) 

This order, comprising some six hundred species only a few of 
which are pathogens, is characterized as follows: mycelium well 
developed, much branched, multiseptate; ascocarps fleshy or 
leathery, free or sunken in the substratum or in a stroma, 
rounded or stellate, for a long time enclosed in a tough cover- 
ing which at maturity becomes torn; paraphyses usually longer 
than the asci, much branched, forming an epithecium. 

Key to Families op Phacidiales 

Ascocarps soft, fleshy, bright colored 1. Stictidaceae, p. 154. 

Ascocarps leathery or carbonous, always 
black 
Ascocarps at first sunken, later strongly 

erumpent, hypothecium thick 2. Tryblidiaceae, p. 155. 

Ascocarps remaining sunken in the sub- 
stratum, hypothecium thin, poorly 
developed 3. Phacidiacese, p. 155. 

Stictidaceae 

The members of this family (about twenty genera and two 
hundred fifty species) are usually considered saprophytes, al- 
though one species of Stictis has recently been described as a 
parasite. 

Stictis Persoon 

Perithecia sunken, pilose, at length erumpent; asci cylindric, 
containing eight filiform, multiseptate spores; paraphyses filiform, 



THE FUNGI WHICH CAUSE PLANT DISEASE 



155 



richly branched apically. Of the seventy 
or more species of the genus only one, 
S. panizzei d Not., originally described 
from fallen oUve leaves in Italy, has been 
charged with producing disease.^^ It has 
within the last few years become very de- 
structive in Italy. 

The Tryblidiaceae, with six genera and 
some seventy species, are likewise chiefly 
saprophytes with the possible exception of 
the two generj^ Heterosphseria and Sclero- 
derris. The former occurs on umbellifere 
while the latter may contain the perfect 
stage of certain currant and gooseberry 
fungi (Mastomyces and Fuckelia) of Europe 
as well as a European parasite of the wil- 
low. 

T-»t. -J" / -I r- A\ FiG- 110. — Stictis. D, 

Phacidiaceae (p. 154) habit sketch, ^.ascus 

and paraphyses. Af- 

Apothecia sunken, more or less erumpent, er e m 
disk-like or elongate, single or grouped, leathery or carbonous, 
black, firm, opening by lobes or rifts. 




Key to Genera of Phacidiaceae 

Apothecia not inseparably united to the sub- 
stratum I. Pseudophacidieae. 

Spores elongate, hyaline, 1-celled 1. Pseudophacidium. 

Spores elongate, spindle-form or filiform, 
multicellular. 
Spores elongate to filiform, not muri- 
form 
Apothecia rounded, opening by a 
rounded mouth 
Spores elongate or spindle-form 

paraphyses, none 2. Dothiora, p. 156. 

Spores elongate-globoid, 2-celled; 

paraphyses present 3. Rhagadolobium. 



156 THE FUNGI WHICH CAUSE PLANT DISEASE 

Spores needle-like ; paraphyses 

present 4. Coccophacidium. 

Apo.thecia elongate; opening by a 

slit 5. CUthris, p. 157. 

Spores elongate, muriform, with pa- 
raphyses 6. Pseudographis. 

Apothecia firmly united to the substratum. 11. Phacidieae. 
Apothecia separate, no stroma 

Spores ellipsoid or globoid, 1 to 4-celled 
Spores 1-celled 

Apothecia rounded 

Paraphyses not forming an epi- 

thecium 7. Phacidium, p. 157. 

Paraphyses forming an epithe- 

cium 8. Trochila, p. 157. 

Apothecia irregular, elongate, 
opening by an irregular 

mouth 9. Cryptomyces, p. 158. 

Spores 2 to 4-celled 
Spores hyaline 

Apothecia rounded, spores 2 to 

4-celled 10. Sphaeropeziza. 

Apothecia elongate, spores 

2-celled 11. Schizothyrium. 

Spores brown 12. Keithia. 

Spores filiform or needle-like, 1 to 

many-celled 13. Coccomyces. 

Apothecia collected on a stroma, opening 
elongate 
Spores 1-celled, hyaline 

Spores ovate 14. Pseudorhytisma. 

Spores filiform or needle-like 15. Rhytisma, p. 158. 

Spores 2-celled 

Spores hyaline 16. Marchalia. 

Spores brown 17. Cocconia. 



Dothiora Fries (p. 155) 

There are about ten wood-inhabiting species. Ascocarp at first 
sunken in the substratum, later irregularly erumpent; disk black; 
asci clavate, 8-spored; spores elongate or spindle-form, many- 



THE FUxNGI WHICH CAUSE PLANT DISEASE 



157 



celled or muriform, hyaline or slightly yellowish; paraphyses 
wanting. 

D. virgultorum Fr. grows on birch. 



Clithris Fries (p. 156) 

A small genus of about twenty species found 
on wood and bark; mainly saprophytes. 

Ascoma sunken, then erumpent, elongate, 
with lip-like margins, dark colored; asci clavate, 
8-spored, often blunt pointed; spores linear or 
spindle-shaped, multicellular; paraphyses fili- 
form, coiled apically, hyaline. 

C. quercina (Pers.) Rehm. is found on oak 
branches and is perhaps identical with C. aureus 
Mass. on willows. C. juniperus is found on liv- 
ing juniper. 



Phacidium Fries (p. 156) 

Over seventy species chiefly on leaves or ^ 

herbaceous stems. Ascoma single, flattened, Fig. in.— Clithris. 

... Asciis with spores 

soon becommg lenticular, breaking open by and paraphyses. 
an irregular rift; asci clavate, 8-spored; spores ^^ '^ ™' 

ovate or spindle-shaped, hyaline, 1-celled; paraphyses thread-like, 
hyaline. Conidial form probably in part =Phyllachora. 
P. infestans Karst. is a parasite on pine leaves. 



Trochila Fries (p. 156) 

Perithecia sunken and closed, later erumpent, black, leathery; 
asci clavate 8-spored; spores long, hyaline, 1-celled; paraphyses 
filamentose forming an epithehum. Fig. 112. 

T. popularum Desm. is thought by Potebnia -^^ and Ed- 
gerton -^^ to be the ascigerous form of Marssonia castagnei 
D. &M. 

T. craterium is the ascigerous form of Gloeosporium para- 
doxum. See p. 541. 



158 THE FUNGI WHICH CAUSE PLANT DISEASE 



Cryptomyces Greville (p. 156) 

A genus of some ten species living on wood or leaves, forming 
large black blotches. 

Ascoma sunken in the substratum, flattened, erumpent, irregu- 
lar in outline, coal black; asci clavate, 8-spored; spores elongate, 
1-celled, paraphyses filiform. 

C. maximus (Fr.) Rehm is a parasite on willow and dogwood 
twigs in Europe and America, forming large carbonous areas 
under the bark. 

Rhytisma Fries (p. 156) 

To Rhytisma belong about twenty-five species which cause very 
conspicuous, though but slightly injurious, black leaf -spots. The 
spots which are white within, are due to sclerotial 
cushions formed in the host tissue. Thickening 
of the leaf occurs in the infected part. One- 
celled conidia (Melasmia form) are abundantly 
produced in pycnidia early in the season, followed 
by sclerotium formation. Much later, usually well 
into winter or the following spring, the apothecia 
miai appear. Besides the asco-spore-producing forms 

Fig. 112. — Tro- several species of which the asco-spores are un- 
and %araphy- known have been referred here, 
ses. After Ascoma on a sclerotial stromatic layer, which 
is black above, white within; ascocarps elongate, 
opening by a lip-like slit; asci clavate, often blunt pointed, 
8-spored; spores filiform or needlelike, hyaline, mostly 1-celled, 
lying parallel and lengthwise of the ascus; paraphyses filiform, 
hyaline, often arched above. 
R. acerinum (Pers.) Fr. 

The spot is at first yellow and thickened and in this stage bears 
numerous conidia upon short conidiophores. The apothecia 
ripen in spring and rupture by numerous irregular fissures which 
follow the ridges of the wrinkled surface. Klebahn secured infec- 
tion by ascospores resulting in three weeks in yellow spots and in 
eight weeks in conidiospores. The conidia are supposed to aid in 



THE FUNGI WHICH CAUSE PLANT DISEASE 159 

spreading the fungus during the summer though they have not 
yet actually been observed to germinate or to cause infection. 

Apothecia radiately arranged on the stroma which is about 
0.5-1.5 cm. across; asci 
120-130 X 9-10 ju; spores 
large, 65-80 x 1.5-3 fj.; 
paraphyses numerous, in- 
curved or hooked. 

Conidia ( = Melasmia 
acerina Lev.) preceding _ 

the asci, producing numerous - ii.^'<^p¥^.{l'X'<l{'j(sf/^'^^^^ 

small, hyaline, 1-celled ^.^r^'"'" 
spores in an extended hy- ^w^i ^ ; n ' 

menial layer. '" ^'~^ ^^^^^^^m^ 

On various species of Fig. 113.— R. acerinum. F, conidial layer; 
maple, apparently consist- ^. ascus and paraphyses. After Tulasne. 

ing of races since in different localities the host differs without a 
crossing over of the fungus. 

R. punctatum (Pers.) Fr. also occurs on maple, especially Acer 
pseudoplantanus. It may be distinguished from the preceding by 
its small, speck-like stromata. 

R. salicinum (Pers.) Fr. is found on willow in Europe and 
America. It is quite similar in external appearance to R. acerina 
except for the smaller average size of the spots. 

R. symmetricum Miill. is another willow inhabiting species. 
The apothecia are amphigenous and are said to mature in autumn 
on the still live leaves. 

Other species are common especially on various Ericaceffi and 
Coniferse in Europe and America. 

Hysteriales (p. 124) 

Small species with elongated, black, covered apothecia which 
open by a long narrow slit exposing the hymenium; asci 8-spored; 
spores usually long and slender. Some few are leaf parasites but 
most are wood saprophytes. Pycnidia are found in some species. 
The order serves as a bridge between the Discomycetes and the 
Pyrenomycetes. About four hundred species. 



160 THE FUNGI WHICH CAUSE PLANT DISEASE 



Key to Families of Hysteriales 

Ascocarps immersed; walls of the ascocarps 
connate with the membranous cover- 
ing 1. Hypodennataceae, p. 160. 

Ascocarps at first immersed, erumpent, 

walls free 
WaUs membranous or coriaceous, black. 2. Dichaenaceae, p. 162. 
Walls thick, almost corky, gray or 

black 3. Ostropaceae. 

Ascocarps from the first free 
Walls carbonous, black; shield-shaped, 
round, oval or more commonly 

linear 4. Hysteriaceae, p. 163. 

Walls membranous or horny, brown, 

ascocarps vertical, clavate 5. Acrospermaceae. 

The third and fifth families contain no pathogens. 



Hypodermataceae 

Ascocarp flattened, rounded or elongate, rarely branched, 
united to the substratum; opening by a slit; asci 4 to 8-spored; 
paraphyses apically branched, the branches forming an epi- 
thecium, or hooked or crimped. About fifty species, chiefly 
saprophytes. 

Key to Genera of Hypodennataceae 

Spores elongate, rather broad 

Spores 1-celled or by cross walls 2 to 
many-celled 
Spores 1-celled 
Asci 8-spored, spores spindlc-form 

Spores hyaline 1. Henriquesia. 

Spores brown 2. Farlowiella. 

Asci 4-spored, spores hyaline 3. Hypodermella, p. 161. 

Spores 2-celled, hyaline 

Apothecium black 4. Hypoderma, p. 161. 

Apothecium red 5. Angelinia. 



THE FUNGI WHICH CAUSE PLANT DISEASE 161 

Spores 4 to many-celled, spindle-form 

Spores 4-celled, mostly hyaline 6. Gloniella. 

Spores 4 to many-celled, brown 7. Rhytidhysterium. 

Spores muriform, hyaline 8. Hysteropsis, p. 161. 

Spores fihform, 1-celled 9. Lophodermium, p. 161. 

Of these genera only four are important here. 

Hypodermella Tubeuf (p. 160) 

This differs from the next genus in its pyriform unicellular 
spores; asci 4-spored. Two species, both European and economic. 
H. larius Tub. affects larch needles in Europe. ^^ 
H. sulcigena Link is on pine needles. 

Hypoderma De Candolle (p. 160) 

Apothecia oblong, opening through a thin black cover by a 
long fissure; asci 8-spored; spores cylindrical or fusiform, 2-celled 
at maturity; paraphyses hooked at the end. 

H. desmazieri Duby,-^^ on pine needles in America and Eu- 
rope. 

Amphigenous; asci broadly clavate, sessile; spores hyaline, 
linear-elliptic, obtuse and 2-rowed. 

H. laricis, H. strobicola, H. pinicola, produce premature leaf 
fall in various conifers. 

Hysteropsis Rehm 

Asci clavate, 8-spored; spores hyaline, muriform; paraphyses 
branched, forming an epithecium. 
H. brasiliensis occurs on cacao trees. 

Lophodermium Chevall 

Spores long, thread-like, continuous; conidiospores in pycnidia. 

L. pinastri (Schr.) Chev. occurs in Europe ^'' and America on 
Pinus sylvestris especially on young plants causing the leaves to 
fall. The first year pycnidia only are formed, the asci not ap- 
pearing until the second year.^^^ 



162 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Ascocarps scattered on the leaf, shining black, up to 1 mm. 
long; asci clavate, 8-spored; spores nearly as long as the ascus, 
90-120 X 1.5 iJL. Conidia cylindric, hyaline, 
continuous, 6-8 x 1 /jl. 
L. brachysporum Rost. 
Perithecia epiphyllous; asci cylindric, short- 
stalked, apex rounded, 120 x 20-25 ju, 8- 
spored; paraphyses bacillar, apex curved; 
spores oblong, 1-rowed, hyaline, 28-30 x 
9-10 /i. 

It is common on pine leaves. ^^^ 
Several other species are parasitic upon 
various conifers, among them: L. macrospo- 
rium (Hart.) Rehm, on spruce leaves, in 
Europe and America; L. nervisequum (D. C.) 
Rehm, on fir leaves, a very destructive 
European species; the pycnidial stage is 
'h, habh skSf"; Septoria pini Fuckel; L. juniperinum (Fr.) 
d Not, on juniper leaves and twigs in 
Europe and America; L. gilvum Rost., on 
pines; L. abietis Rost., on spruce leaves; L. laricinum Duby, on 
larch. The last four species are European. 




ascus and paraphy- 
ses. After Rehm. 



Dichaenaceae (p. 160) 
This family contains the single genus Dichsena. 



w(kl 



Dichaena Fries 

Apothecia grouped in rounded spots; at 
first sunken, then erumpent, rounded or elon- 
gate, dark brown; asci irregularly pyriform, 4 
to 8-spored; spores ellipsoidal, at first 1-celled, ^j- --^^vi^^^^^^^i. 
at maturity multicellular; paraphyses filiform, pio. 115.— Hysterium 
Some seven species are found upon various rnamjsporum. Af- 
trees. 

D. quercina Fr. causes rough black patches on bark of young 
oaks in Europe and America; D. faginea Fr., a similar effect on 
beech. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



163 



Hysteriaceae (p. 160) 

Ascocarps free, seated upon the substratum, 
elongate or linear, straight, curved or even 
branched, disk-form, boat-shaped or band-like, 
black; asci usually 8-spored; paraphyses fila- 
mentous, often forming an epithecium. 

About fourteen genera and some two 
hundred fifty species, many but poorly 
known. Several genera contain plant patho- 
gens, but they are not often of economic im- 
portance. 




Fig. 116. — D. quer- 
cina. Ascus and 
paraphyses. After 
Rehm. 



2. Aulographum. 



Glonium. 
Hariotia. 



Key to Genera of Hysteriaceae 

Ascoma linear, flattened, broadly sessile 
Spores ellipsoid or spindle-shaped, many- 
celled 

Spores 1-celled, 16 in each ascus 1. Cyclostomella. 

Spores 2-cellcd, sometimes 4-celled, 
ellipsoid or elongate 
Spores hyaline 

Asci 8-spored, spores 2 to 4-celled 
Paraphyses scarcely branched. . 
Paraphyses forming an epithe- 

cimii 3. 

Asci many-spored, spores 2-celled. 4. 
Spores colored, 2-celled; leaf infect- 
ing fungi 
Paraphyses present 
Ascoma seated on a cottony 

stroma 5. Lembosia. 

Ascoma radial, on a circular 
stroma 
Spores 2-celled, 8 in each 

ascus 6. Parmularia. 

Paraphyses absent, stroma irreg- 
ularly circular 7. Hysterostomella. 

Spores 4 to 8-celled, elongate or spindle- 
form 
Spores hyaline, spindle-form, 4- 

celled. 8. Hysteroglonium. 



164 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Spores brown, elongate, 4 to 

8-celled 9. Hysterium. 

Spores elongate, muriform 10. Hysterographium, p. 164. 

Ascoma boat or band-shaped, not sessile 
Spores spindle-formed, brown, many- 
celled 
Spores 4 to 8-celled; asci 8-spored. 11. Mytilidium. 
Spores many-celled ; asci 4-spored . 12. Ostreion. 
Spores filamentose, hyaline or yellow 13. Lophium. 
Ascoma stellate 14. Actidium. 

Hysterographium Corda 

Asci clavate, 8-spored; spores muriform, dark colored when 
mature; paraphyses branched forming an epithecium. About 
seventy species. 

H. fraxini (Pers.) de Not. occurs on Oleacese, particularly on 





Fig. 1 17. — H. 
fraxini. Ascus 
and paraphyses. 
After Rehm. 





Fig. 118. — Gymnoaseus, sexual organs. 
After Dale. 



the ash, perhaps only as a saprophyte. It is found both in Europe 
and America. 

Aspergillales (p. 124) 

The Aspergillales are clearly distinguished from the other 
Ascomycetes by the possession of a closed ascocarp in which the 
asci are not collected in a hymenium but are irregularly scattered. 
The forms with the least developed peridium are evidently related 



THE FUNGI WHICH CAUSE PLANT DISEASE 165 

to the Endomy cetaceae ; the forms with a more highly developed 
peridium, to the Pyrenomycetes, particularly to the Perisporiales. 
Conidial forms are usually present, indeed in many cases they 
preponderate almost to the entire exclusion of the ascigerous form 
which may be seen only under very exceptional conditions. 

Sexual reproduction has been demonstrated in several families. 
In the Gymnoascacese (Dale ^^ and Eidam ^^) there are usually two 
twisted branches (Fig. 118) which conjugate. These branches 
are multinucleate at the time of fusion. The ascogonium de- 
velops from this fertilization much as is described on pages 116- 
117. In the Aspergillacese similar sexual organs are formed but 
parthenogenesis or a much reduced form of fertilization is often 
met. In all, the species number two hundred fifty or more. 

Key to Families of Aspergillales 

Peridium made up of loose floccose hyphse . 1 . Gymnoascacese. 
Peridium compact, closed 

Ascocarps mostly small, not subterranean 
Ascocarps mostly sessile without 

stroma; peridia remaining closed. . 2. Aspergillaceae, p. 166. 
Ascocarps mostly stalked ; peridia open- 
ing at maturity by lobes, or ir- 
regularly 3. Onygenaceae. 

Ascocarps sessile, the spores issue in 
columnar masses from the goblet- 
shaped peridia 4. Trichocomaceae. 

Ascocarps sessile on a small stroma. . . 5. Myriangiaceae, p. 170. 
Ascocarps mostly enlarged, tuberous, sub- 
terranean. 
Peridium clearlj' distinct from the 
walls of the ascocarp ; spore masses 

powdery at maturity 6. Elaphomycetaceae. 

Peridium not clearly limited, continu- 
ous with the walls of the ascocarp; 
spore masses never powdery 7. Terfeziaceae. 

Of these the second and fifth families only contain pathogens. 
The Gymnoascacese of five genera and some fifteen species are 
found on manure, and other organic matter. The third and fourth 



166 THE FUNGI WHICH CAUSE PLANT DISEASE 

families are monogeneric; the third on hoofs, horn, etc.; the 
sixth is subterranean and the Terfeziacese more or less subter- 
ranean. 

Aspergillaceae (p. 165) 

The ascocarp, in many forms but rarely seen, is a small spherical 
or tuber-shaped body, usually indehiscent, rarely opening by a 
pore. The spherical or pyriform asci bear from 2 to 8 spores which 
may be from 1 to many-celled. The ascocarp is in some genera 
provided with appendages which strongly resemble these of 
the Erysiphaceae (Microascus). Conidia are produced in great 
abundance. 

In Aspergillus and Penicillium fertilization is said by some 
observers to be accomplished by conjugation of a straight oogo- 
nium with a spirally coiled antheridium, this act resulting in an 
ascogenous hypha. Recent work of Dale ™ (see also Fraser and 
Chambers '^^) denies such fusion in one species of Aspergillus 
which she studied, though sexual organs were often present, 
and predicates a reduced form of sexuality consisting of fusion 
of the nuclei of the ascogonium with each other. 

Key to Genera of Aspergillaceae 

Spores 1 -celled 

Perithecium flask-shaped, beaked or papil- 
late 1. Microascus. 

Perithecium not beaked 

Perithecium with hair-like appendages; 
peridium compact, mostly dark 
colored 
Appendages straight hairs or forming 

a hairy felt 2. Cephalotheca. 

Appendages apically coiled hairs. ... 3. Magnusia. 
Perithecium unappendaged ; peridium 
membranous or fleshy 
Conidia borne directly on the myce- 
lium 
Chlamj'^dospores borne in chains. . 4. Thielavia, p. 167. 
Chlamydospores borne singly 5. Rostrella, p. 168. 



THE FUNGI WHICH CAUSE PLANT DISEASE 167 

Conidia borne on distinct conidio- 
phores 
Conidia borne singly; conidio- 
phores branching at right 

angles 6. Aphanoascus. 

Conidia borne in chains 

Conidiophorcs simj)le, aggre- 
gated into bundles 7. Emericella. 

Conidiophorcs enlarged apically 
bearing numerous sterig- 
mata 

Sterigmata simple 8. Aspergillus, p. 168. 

Sterigmata branched 9. Sterigmatocystis. 

Conidiophores, sympodially 

branched 10. Eurotiopsis. 

Conidiophores bushy branched 
Conidiophores single, peri- 

thccia sessile 11. Penicillium, p. 169. 

Conidiophorcs in bundles, api- 
cal cells swollen, peri- 

thecia stalked 12. Penicilliopsis. 

Spores 2-celled; peridium at maturity stel- 
late 13. Testudina. 

Of the thirteen genera and some one hundred to two hundred 
species only four of the genera are of interest here. The others 
occur on rotting leaves, manure, etc. 

Thielavia Zopf ^-'^^ (p. 166) 

T. basicoia (B. and Br.) Zopf. 

This, the one species of the genus, is on the boundary between 
the Aspergillales and the Perisporiales and is classed by some with 
the one, by some with the other order. 

The ascocarps, which are the form less commonly seen, are 
round, brown, completely closed and have no appendages. The 
asexual spores are of two kinds. First: hyaline conidia produced 
endogenously within "pistol-formed" conidiophores from the 
ends of which they are expelled. Second: short cylindrical conidia 
or chlamydospores with a thick brown wall; borne in series of 



168 



THE FUNGI WHICH CAUSE PLANT DISEASE 



three to six on the ends of hyahne branches, Fig. 119. These 
conidia fall apart as they age. 

The hyaline conidia preponderate in early disease, giving the 
surface of the root a mildewed appearance; the dark conidia pre- 
ponderate later, covering the 
root with a black coating. 
Finally, after the host is dead, 
the ascocarps appear. 

The delicate hyaline myce- 
lium wanders through the 
affected root disorganizing its 
tissue. The superficial myce- 
lium is lightly tinted. 

Perithecia 80-100 /i; asci 
ovate, 8-spored; spores len- 
ticular, vacuolate, 1-celled, 
chocolate-colored, 8-12 x 
4-5 Ai; chlamydospores in 
chains, at maturity separa- 
ting, short-cylindric, about 
5-8 X 12 /i; the entire group 
25-65 /i long; conidia hyaline 
about 10-20 X 4-5 ^l. 

In Europe and Eastern 
North America on Aralia quinquefolia, Begonia rubra, Begonia 
sp., Catalpa speciosa, Cyclamen sp., Gossypium herbaceum, 
Linaria canadensis, Lupinus angustifolius, L. albus, L. luteus, 
L. thermis, Nasturtium armoracea, Nemophila auriculata, Nico- 
tiana tabacum, N. rustica, Onobrychis cristagalli, Oxalis stricta, 
Phaseolus vulgaris, P. multiflorus, Pisum sativum, Senecio elegans, 
Trifolium repens, Trigonella coerulea, Vigna sinensis and Viola 
odorata. 

Rostrella cofifeae Zimm. is described as the cause of canker of 
coffee in Java."^ 

Aspergillus Micheli (p. 167) 

The ascocarps are small, spherical, indehiscent, smooth bodies 
which at maturity are entirely filled with 8-spored asci; spores 




Fig. 119. — Thiclavia basicola, showing two 
conidial forms and ascus and ascospores. 
After Van Hook and Zopf. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



169 



1-celled. The conidiophores, which serve better to characterize 
the genus, are swollen at the end, and bear numerous sterigmata 
(Fig. 120) on which the spores are borne basipetally in chains. 
Sclerotia are sometimes formed. 

The members of the genus are all saprophytes but some of them 




Fig. 120. — Asper- 
gillus, c o n i d i o- 
phore. After 
King. 




Fig. 121. — Penicillium, 
showing a conidio- 
phore; a, producing 
chains of conidia, c; 
s, three spores more 
highly magnified. 
After Longyear. 



cause injury to fruit in the tropics; for example, A. ficuum, Reich, 
on figs; A. phoenicis Pat. & Del. on dates. 



Penicillium Link "^ (p. 167) 

The ascocarp is much as in the last genus, with the asci 4 to 
8-spored. It may develop directly from the mycelium or with the 
intervention of a sclerotial stage. The characteristic conidiophore 
serves to distinguish the genus by its mode of branching. Fig. 121. 
Instead of being apically swollen as in the preceding genus it 
branches repeatedly, the branches bearing terminal sterigmata 
and giving the conidiophore the appearance of a brush; hence the 
name. For species see page 573. 



170 THE FUNGI WHICH CAUSE PLANT DISEASE 



Myriangiaceae (p. 165) 

Perithecia numerous upon or in a stroma; asci in a pseudo- 
parenchymatous substance within the perithecium; spores muri- 
form. 

Key to Genera of Myriangiaceae 

Stroma valsoid, perithecia superficial ... . 1. Myriangium. 
Stroma effused, perithecia immersed. ... 2. Myriangiella, p. 170. 

Myrangiella orbicularis Zimm. parasitizes coffee in Java.^°° 



Pyrenomycetes 



52 



The four following orders are usually grouped together as the 
Pyrenomycetes ; separated from the preceding forms by their closed 
ascocarp with the asci arranged in a hymenium. They constitute 
a vast assemblage of more than ten thousand species, the large 
majority saprophytic and unimportant except in the general 
economy as scavengers. 

Perisporiales (p. 124) 

The present order is characterized by its almost universal 
parasitic habit, the evident mycelium and the globoid perithecia 
without ostioles, or in one family flattened, ostiolate perithecia. 
The mycelium is superficial upon the host and frequently quite 
conspicuous. 

Key to Families of Perisporiales 

Perithecia mostly spherical, imperforate 
Mycelium white; perithecia with append- 
ages 1. Erysiphaceae, p. 171. 

External mycelium dark colored or want- 
ing, perithecia without true append- 
ages, but sometimes surrounded by 

appendage-like hyphae 2. Perisporiaceae, p. 189. 

Perithecia flattened, shield-shaped, ostio- 
late 3. Microthyriaceae, p. 195. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



171 



Erysiphaceae (p. 170) 



46. 52. 77. 78 




Fig. 122. — I, E. graniinis, showing branching 
haustoria. 33, Phyllactinia, intercellular 
hyphffl. After Smith. 



This family on account of its abundance everywhere, its sim- 
plicity of structure, and its possession of typical ascigerous and 
conidial stages forms a favorite type for introductory study of the 
Ascomycetes. Its members 
are easy of recognition, form- 
ing a coating of white conidia, 
conidiophores and mycelium 
upon the surface of its hosts 
and giving them an appear- 
ance much as though they had 
been lightly dusted with flour. 
Later in the season the white 
patches are more or less 
liberally sprinkled with the 
black perithecia leading to 
the common name powdery 
mildew. An important list 
of the economic forms and their hosts has been published by 
Halsted." 

The mycelium except in Phyllactinia is entirely superficial. It 
is usually quite hyaline and is branched, septate and its cells 
uninucleate. It fastens to the host and penetrates its epidermal 
cells by uninucleate haustoria which by their various lobings aid 
in specific characterization. Figs. 122, 123. 

Haustoria may be grouped in three general classes; (1) those 
arising directly from the lower surface of the mycelium; (2) those 
arising at the side of the mycelium as small semicircular processes ; 
(3) arising from more or less deeply-lobed lateral swellings of the 
mycelium. The relation of the haustoria to the host cells has 
been extensively studied by Smith.*^^ 

The conidia arise in basipetal succession on simple scattered 
conidiophores (Fig. 129); are hyaline, oval or barrel-shaped, 
smooth, 1-celled. Neger has shown that they vary greatly in size 
with nutrition conditions .^° 

Conidia germinate readily at once in dry air, better in humid 
air, producing from one to three germ tubes. Haustoria are 



172 



THE FUNGI WHICH CAUSE PLANT DISEASE 




c 



^Ii9 



formed at once and the mycelium develops to a more or less 
circular colony, producing new conidia in a few days. Artificial 
inoculations on susceptible plants, using conidia, usually result 
within two to five days in typical mildew spots. 

Neger,^° who studied the germination of conidia extensively has 
shown that light hastens the growth of the germ tubes, which in 
many cases are negatively phototropic. Con- 
tact stimulus leads to the growth of appres- 
soria. 

The perithecia are subspherical, often some- 

^ what flattened, white to yellow when young, 

Fig. 123. — Erysiphe, , , , , , , • i , , 

showing lobed haus- dark to blacK and reticulated when mature; 

toria. After Salmon. ^^^ without OStiole but are provided with 

appendages of various types. Figs. 130, 133-136, which give main 
characters to mark the genera. The appendages serve by hygro- 
scopic movements to aid in the distribution of the fungus.^^ The 
ascospores become free after dissolution of the perithecium by 
weathering. The asci are either solitary or quite numerous within 
the perithecium and bear two to eight hyaline spores each. 

The conidia are short-lived summer spores. The perithecia 
mature more slowly and constitute the hibernating condition. 
In some instances the ascus-form is unknown; 
the fungus is then classified solely by its 
conidial stage and falls under the form genus 
Oidium (see p. 569.) 

In Sphserotheca ^^ an antheridial and an 
oogonidial branch, each uninucleate, are de- 
veloped, and cut off by septa. The oogo- 
nium enlarges; the antheridium lengthens, Fig. 124.— Ascogomum- 
its nucleus divides, and a septum is run in \ube with five nuclei. 

' ^ ^ After Harper. 

separating the stalk cell from the antheri- 
dium. The sperm nucleus enters the oogonium and fuses 
with the oogonial nucleus. Simultaneous with fertilization oc- 
curs, from the stalk cell of the oogonium, the development of 
a sterile system of enveloping threads which surround and pro- 
tect the fertilized oogonium and eventually mature into the 
sporoearp. The fertilized oogonium divides several times trans- 
versely producing a series of cells, one of which is binucleate. 





THE FUNGI WHICH CAUSP: PLANT DISEASE 173 

This binucleate cell after fusion of its nuclei develops into the 
one ascus characteristic of the genus. The ascus nucleus by 
division gives rise to the spore nuclei and the spores are cut out of 
the periplasm by reflexion of the astral rays. 

In Erysiphe ^^ the oogonium and antheridium arise in a very 
similar way, the oogonium being somewhat curved. Fertilization 
is also similar consisting of the union of two gametic nuclei. After 
fertilization the oospore nucleus divides and the oogonium de- 
velops into a short bent tube, which contains from five to eight 
nuclei. Septa now appear cut- 
ting off cells, some uninucleate, 
some with two or more nuclei. 
The ascogenous hyphse develop 
a knot and soon divide into 
two or three cells each and 
give rise to the asci which are 
in the beginning binucleate. 

T _,^, ,, , • • 04 ,1 Fig. 125. — Phyllactmia, male and female 

In Fhyllactmia "** the OOgO- branches; uninucleate oogonium and 
nium, antheridium and fertili- '^^theridium. After Harper. 

zations are as in Erysiphe, though the oogonium may be quite 
curved so as to make almost a complete turn around the anther- 
idium. Fig. 125. 

After fertilization the antheridium degenerates and enveloping 
protective hyphse arise both from the oogonium and the antheridium 
stalk cells. The oogonium becomes three to five nucleate and 
develops to a row of cells of which the penultinate cell has more 
than one nucleus. The ascigerous hyphse arise from this binu- 
cleate cell, perhaps also from other cells of the series, become 
septate and form the asci either terminally, laterally or inter- 
calary. The young ascus is binucleate, fusion follows and the 
spores develop as in the preceding genera. 

The family contains, according to Salmon, forty-nine species 
and eleven varieties, according to Saccardo more than one hun- 
dred species. These are parasitic on some one thousand five 
hundred hosts, some of them upon economic plants and of 
serious harmfulness. 

The matter of delimiting species and even genera is often diffi- 
cult, owing to intergrading forms. This question is complicated 



174 THE FUNGI WHICH CAUSE PLANT DISEASE 

still further by biologic specialization such that forms which are in- 
distinguishable under the microscope show in inoculation tests dif- 
ferent abilities regarding host infection. Thus Neger,^° Salmon,^^' ^^ 
Reed,^'' and others have shown that spores borne on a particular 
host are capable of infecting only that host or in other cases only 
nearly related species of the same host genus. Forms which can 
pass from one genus to another are less common. Forms morpho- 
logically distinct are regarded as separate species. Differentiations 
within such species, regarding the species of host plant which they 
parasitize, give rise to "biologic species" or "biologic varieties," 

Reed ^'' writes of these biologic forms thus: 

"So far as investigated, Erysiphe cichoracearum, is the only 
one with doubtful exceptions, . . . shown to be capable of in- 
fecting plants belonging to more than one genus." 

"There are other cases where the mildew is limited closely to 
plants of a single genus," and "Several cases are recorded where 
the mildew from one species will not infect other species of the same 
genus. Most of these claims, however, rest on insufficient data." 

Some morphological species show a very wide range of hosts; 
one species, Phyllactinia corylea is known on forty-eight genera 
in twenty-seven families, others are limited to single genera or 
to single species of host plant. Two, three, and even five species 
are recorded for some species of host. 

Geographically the Erysiphacese are widely distributed, prac- 
tically of world distribution, but they are more abundant in the 
temperate zones than elsewhere. 

A pycnidium-bearing parasite, Cicinnobolus, p. 494, is quite 
frequently found on the mycelium and conidiophores of the Ery- 
siphacese. 

Owing to the extreme variability of the perithecial characters 
and the almost promiscuity of host selection this family presents 
a most difficult problem to the taxonomist who must either segre- 
gate or "lump " species. No middle ground seems open at present. 

Key to Subfamilies and Genera op Erysiphaceae 
Mycelium wholly external to the tissues of the 
host plant, usually sending haustoria 
into the epidermal cells only, perithecial 
appendages various, more or less flaccid I. Erysipheae. 



THE FUNGI WHICH CAUSE PLANT DISEASE 175 

Perithecial appendages indeterminate, 
similar to the mycelium, simple or ir- 
regularly branched 
Pcrithecia containing a single ascus. . . 1. Sphaerotheca, p. 175. 

Perithecia containing several asci 2. Erysiphe, p. 177. 

Perithecial appendages determinate 
Appendages hooked or coiled al the 

apex 3. Uncinula, p. 180. 

Appendages dichotomous at the apex 

Perithecia containing a single ascus. 4. Podosphaera, p. 182. 
Perithecia containing several asci ... 5. Microsphaera, p. 185. 
Mycelium with special intercellular haus- 
toria-bearing branches which enter the 
host by the stomata; perithecial ap- 
pendages rigid, with a bulbous base. . . II. Phyllactinieae. 
A single genus 6. Phyllactinia, p. 187, 

Sphaerotheca, Leveille 

Perithecia subglobose; appendages floccose, brown or hyaline, 
spreading horizontally and often interwoven with the mycelium, 
simple or vaguely branched, frequently obsolete; ascus single, 
8-spored. Five species, accorcUng to Salmon; Engler and 
Prantl give fourteen. 

S. humuli (D. C.) Burr.^s-s^ 

Amphigenous; mycelium usually evanescent; perithecia usually 
somewhat gregarious, but varying from scattered to cespitose, 
58-120 n in diameter; cells small, averaging 15 n; appendages 
few or numerous, usually long, often exceeding nine times the 
diameter of the perithecium, more or less straight, septate, dark 
brown throughout: variations are, short, flexuose, pearly-brown, 
white or even obsolete. Ascus broadly-elliptic to subglobose, 
rarely abruptly stalked, 45-90 x 50-72 /a; spores 20-25 x 12-18 n, 
rarely larger, averaging 22 x 15 n. 

Conidia ( = Oidium fragariae) ovate, white, membrane smooth. 

Salmon^'' has shown that subjecting the conidia of this variety 
to low temperature, 0° two hours, increases their germinating power. 
Sowing ascospores from the hop, on hop, Potentilla and Spirea he 
secured infection only on the hop.^^ Conidia from hop infected 
hop but not Spirea. 



176 



THE FUNGI WHICH CAUSE PLANT DISEASE 



The species is cosmopolitan and among its numerous hosts are 
the economic genera Dipsacus, Fragaria, Humulus, Phlox, Pyrus, 
Rosa, Ribes, Rubus, Scabiosa, Spirea and Viola. 

It is a common rose mildew of America and England and is also 
especially destructive on the strawberry. 
S. humili var. fuliginea. (Schl.) Sal. 

Perithecia usually smaller than in the last, sometimes only 50 /x 
in diameter, wall usually harder and more brittle, cells larger, ir- 
regularly shaped, averaging 25 fi; 
appendages usually short, pale 
brown; spores 20-25 x 12-15 /x- 

Throughout Europe, Asia and 
North America. 

It is recorded on Arnica, 
Calendula, Coreopsis, Fragaria, 
Gaillardia, Impatiens, Phlox, 
Scabiosa, Taraxacum, Verbena, 
Viola, and several other non- 
economic genera. 

S. pannosa (Wallr.) Lev.^-"^^ 
Mycelium persistent, forming 
dense satiny patches on the 
stem, calyx, petiole, and rarely 
on leaves, at first shiny white, then becoming gray, buff or 
rarely brown; perithecia more or less (usually completely) im- 
mersed in the persistent mycelium, globose to pyriform, 85-120 n 
in diameter, usually about 100 fj,; cells obscure, about 10 fi wide; 
appendages few, often obsolete, very short, tortuous, pale brown, 
septate; ascus broadly-oblong to globose, 88-115 n, averaging 
100 X 60-75 fi; spores 20-27 x 12-15 m- 

Conidia ( = Oidium leucoconium) ovoid, 20-30 x 13-16 n, 
hyaline; conidiophores short. 

Hosts: peach and rose; cosmopolitan. 

The conidia are very common on the rose, but the perithecia 
are rare. What often passes for this species on roses in America 
is in reality S. humili." 

S. mors-uvae (Schw.) B. & C.^^"^^ 

The mycelium at first white, is exceptional among the Erysipheae 




Fig. 126. — S. mors-uvae, a perithecium 
discharging its single ascus which 
contains eight spores. After Long- 
year. 



THE FUNGI WHICH CAUSE PLANT DISEASE 177 

in that it later becomes quite brown. It is found in closely felted 
patches on stems and fruit. Perithecia begin to form in June. 

Amphigenous; mycelium persistent, at maturity forming dense 
pannose patches of brownish hyphae; perithecia gregarious, more 
or less immersed in the persistent mycelium, subglobose, 76-110 
/i in diameter; cells large, at first well defined, then becoming 
obscure, 10-25 n wide; appendages usually few or even obsolete, 
pale-brown, short, rarely longer, up to five times the diameter of 
the perithecium, tortuous; ascus elliptic-oblong to subglobose, 
70-92, rarely 100 x 50-62 m; spores 20-25 x 12-15 /x. 

On wild and cultivated species of Ribes in America; recently 
introduced into Europe where it is very destructive. 

S. lanestris Hark, occurs on various species of oaks in the United 
States. 

Erysiphe Hedwig (p. 175) 

Perithecia globose, or slightly depressed, rarely concave; ap- 
pendages floccose, simple or irregularly branched, sometimes 
obsolete, usually more or less similar to the mycelium and inter- 
woven with it; asci several, 2 to 8-spored. 

Salmon recognizes eight species; Engler and Prantl,"' twenty. 

E. polygoni D. C.^^ 

Amphigenous; mycelium very variable, persistent, thin, effused 
and arachnoid, rarely thick, or more often evanescent; perithecia 
gregarious or scattered, usually rather small, 
averaging 90 /x, but ranging from 65 to 180 ix; 
cells usually distinct, 10-15 n wide; append- 
ages very variable in number and length, 
few or many, distinct or more or less inter- 
woven with the mycelium, brown or colorless; ^ -.^^ ^ 

•^ . ,, . Fig. 127.— E. polygoni, 

asci 2-8 or rarely as many as 22, variable m the asci. After Sal- 
shape and size, usually small and ovate, with 
or without a short stalk, 46-72 x 30-45 fx; spores 3-8 rarely 2, 
19-25 X 9-14 M- 

Conidiophores ( = Oidium balsamii) medium; conidia ovate, 
hyaline. 

One of the commonest species, especially destructive to the pea 
and turnip. It was studied by Salmon on one hundred ninety host 




178 



THE FUNGI WHICH CAUSE PLANT DISEASE 



species belonging to eighty-nine genera; one hundred forty-six 
more hosts, some doubtful, are reported. Among the economic 
host genera are Adonis, Alyssum, Anemone, Aquilegia, Brassica, 
Calendula, Catalpa, Clematis, Cucumis (?), Cucurbita (?), Dahlia, 
Daucus, Delphinium, Diervilla, Dipsacus, Fagopyrum, Lupinus, 
Lycopersicum, Medicago, Pseonia, Phaseolus, Pisum, Tragopogon, 
Trifolium, Verbena, Vicia, Scabiosa, Symphytum, Valeriana. 

This is the most variable species of this genus varying widely 
in its every character. It includes several species which have by 

some been set aside as distinct, e. g., 
E. martii, E. umbelliferarum and 
E. liriodendri. 

Salmon ^^ found that the conidia 
of this form grown on Trifolium 
pratense were unable to infect other 
species of Trifolium. 

E. cichoracearum D. C.^^ 
Amphigenous; mycelium usually 
evanescent, rarely persistent, white 
or sometimes pink; perithecia gre- 
garious or scattered, 80-140 or 
rarely 180 p.; cells variable, often 
very distinct, 10-20 ju; appendages 
variable in number and size, some 
Fig. 128.— E. cichoracearum, asci shade of brown; asci usually nu- 

and spores. After Salmon. , -, ^ -, ^ i 

merous, about 10-15, but varymg 
from 4 to 36, variable in size and shape, narrowly ovate or 
subcylindric to broadly-ovate, more or less stalked, 58-90 x 
30-35 m; spores 2, rarely 3, 20-28 x 12-20 At. 

Conidiophores ( = Oidium ambrosise Thum), short; conidia 
minute, elliptic, white, 4-5 x 7-5.3 ix. The species is quite vari- 
able sometimes closely approaching E. polygoni. 

Cosmopolitan. The hosts are very numerous, among them 
being: Borago, Calendula, Centaurea, Cichorium, Clematis, 
Cucurbita, Dahlia, Helianthus, Humulus, Mentha, Nicotiana, 
Phlox, Tragopogon, Valeriana, Verbena, Symphytum. It is of 
especial import on composites and cucurbits. 

Reed ^^ has made very extensive culture studies of this species 




THE FUNGI WHICH CAUSE PLANT DISEASE 179 

and concludes that the same form of ''Erysiphe cichoracearum 
D. C, occurs on at least eleven species of the cucurbits, belonging 
to seven genera, infection occurring in these cases in fifty per cent 
or more of the trials. Six other species were also infected, but in 
a smaller percentage of cases. ... It is also plain that the biologic 
form of Erysiphe cichoracearum, occurring on so 
many cucurbits is not entirely confined to the 
species of this one family. Out of fifty-four 
leaves of Plantago rugelii, a species belonging to 
the Plantaginacese, which were inoculated, ten 
became infected. . . . Furthermore out of ten 
leaves of squash seedlings, inoculated with conidia 
from plantain, six became infected . . . and the 
sunflower, Helianthus annuus, was infected in 
thirty-five per cent of the trials in which conidia 
from the squash were sown on leaves of seed- 
lings. . . . The cucurbit mildew could not be 
transferred to asters and goldenrods nor was the 
mildew occurring on these in nature able to in- 
fect the squash. Neither the aster mildew nor 
the cucurbit mildew proved able to infect a 
goldenrod, Solidago csesia. Nor was the mildew 
on this host able to infect asters or squashes." 

E. taurica Lev. is found in Europe, North 
Africa and Asia on Capparis, Cicer, Clematis 
and various other hosts. 

E. graminis D. C. Fig. 129.— e. gra- 

. minis, conidial 

Usually epiphyllous, rarely amphigenous; myce- stage. After Sal- 
lium more or less persistent, forming scattered ™°"' 
patches, at first white, then brown or gray; perithecia large, 
135-280 fi, usually about 200 n, scattered or gregarious, cells ob- 
scure; appendages rudimentary, few or numerous, very short, 
pale brown; asci numerous, 9-30, cylindric to ovate-oblong, more 
or less long-pedicellate, 70-108 x 25-40 fx; spores 8, rarely 4, 
20-23 X 10-13 /x, seldom produced on the living host plant. 

Conidial form ( = Oidium monilioides) with a grayish cast; coni- 
diophores medium tall ; conidia ovoid, white or sordid, 25-30 x 8-10 ju. 

It is found on a large number of species of the Gramineae in- 




180 THE FUNGI WHICH CAUSE PLANT DISEASE 

eluding species of Avena, Festuca, Hordeum, Phleum, Poa, Sac- 
charum, Secale, and Triticum. 

The asci are peculiar in that they usually contain undifferenti- 
ated granular protoplasm, not spores, though in some cases the 
spores, normally 8, are present. Wolff ^^'^ found that after a few- 
days in water the undifferentiated ascoplasm developed spores 
which proceeded to normal germination. 

This species on grasses shows no morphological differences, yet 
inoculation tests have revealed in it numerous biologic varieties. 
Reed^^ summarizes the results of his own work together with 
that of Marchal ^"^ and Salmon ^"^ as follows: 

"So far as tested, all species of Avena are susceptible to the 
oat mildew. All species of Triticum are likewise susceptible to 
the wheat mildew. We find, however, that certain varieties of 
Triticum dicoccum are practically immune to the wheat mildew. 
Other varieties of this same species are entirely susceptible. Some 
species of Hordeum are immune to the barley mildew, and the 
same seems to be true of certain species of Secale with reference 
to the rye mildew. 

To these general statements there are two possible exceptions. 
Marchal states that the oat mildew will infect Arrhenatherum 
elatius. Salmon, however, obtained a negative result with the 
oat mildew on this grass. The evidence is not conclusive either 
way. The other exception is that, according to Salmon, conidia 
from wheat can infect Hordeum silvaticum. 

' It would seem then that under normal conditions there are 
well-defined forms of Erysiphe graminis occurring respectively 
on the species of each of the four cereals." 

It is thought that some hosts may act as bridging species and 
enable the parasite to pass from one host to another to which it 
could not pass directly. 

Uncinula Leveille (p. 175) 

Perithecia globose to globose-depressed; appendages simple or 
rarely once or twice dichotomously forked, uncinate at the apex, 
usually colorless, rarely dark brown at base or throughout; asci 
several, 2 to 8-spored. 

There are eighteen or twenty species. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



181 



U. necator (Schw.) Burr.io^' ^o^' ^o^ 

Amphigenous; mycelium subpersistent; perithecia usually epi- 
phyllous, occasionally hypophyllous or on the inflorescence, 
more or less scattered, 70-128 n; cells distinct, rather irregular 
shape, 10-20 /x; appendages very variable in number and 



m 

length, 7-32, rarely up to 40, 1 to 4-times the diameter of the 
perithecium, septate, thin walled, light or dark amber-brown bas- 
ally, rarely branched, asci 4-6 rarely up to 9, broadly-ovate or 
ovate-oblong to subglobose, with or with- 
out a short stalk, 50-60 x 30-40 n; spores 
4-7, 18-25 X 10-12 fi. 

Conidial form ( = Oidium tuckeri), coni- 
diophores short; conidia elliptic, oblong, 
or obtusely rounded, 2 to 3-catenulate, 
hyaline, 25-30 x 15-17 /x. 

Hosts Vitis, Ampelopsis and Actinidia. 
One of the worst pests- of the family. 

The mycelium is thin walled and spar- 
ingly septate. The haustoria arise from 
lobed lateral swellings of the hyphae, 
penetrate the epidermis with a filamen- 
tous projection and swell within the host 
cell to a bladder-like body. The para- ^-^ — ttv 

sitized cells and later the neighboring pi^ 130— u. necator. 11 
ones turn brown and die. Sa\t?Tnf a.^ef ' iT 

The conidia germinate readily in moist Group of asci removed 

,. /. ,, r from perithecium emit- 

air or m water, sendmg forth trom one ting s, ascospores. After 
to several germ tubes. ^' 

The perithecia are found well developed as early as June or 
July in the United States and are rather evenly scattered over 
the affected surfaces. Bioletti ^'^^ says that a period of warm moist 
weather which favors luxuriant mycelial growth, followed by sud- 
den lowering of temperature to about 50° F., favors their most 
rapid formation. They are at first hyaline, later brown. After 
their form and walls become definite, usually during winter, the 
appendages develop as outgrowths from the outer walls. During 
winter the appendages break off. Galloway ^°'* failed to secure 
germination of ascospores earlier than February or March, but 




182 



THE FUXGI WHICH CAUSE PLANT DISEASE 



perithecia which had been exposed to the weather until spring 
and were then placed in a hanging drop culture afforded spores, 
some of which grew though many of them burst as they emerged 
from the perithecium. Ascospores are known to have remained 
viable for at least eighteen months. ^°^ No successful infections 
were made from ascospores. 

Though perithecia are frequently found in America they were 
not found in Europe until 1892 ^*'' and are now found there but 
rarely. It appears that in their absence the fungus hibernates in 





.1 B 

Fig. 131. — U. necator. Photomicrographs of perithecia on surface of leaf. 

A, Magnified 8 times. B, Magnified 35 times. After Bioletti. 

specially resistant cells of the mycelium which develop within 

• 330 

knotty swellings near the haustona. 

U. salicis (D. C.) Wint. on willow and poplar in Europe, Asia, 
and America, U. aceris (D. C.) Sacc. and U. circinata C. &. P. 
on maple are common species. U. flexuosa Pk. occurs on tEscuIus. 
and elm, U. clandestina (Biv.) Schr. on elm, U. prunastri (D. C.) 
Sacc. on species of Prunus, especially P. spinosa in Europe. U. 
mori Miy. is on Morus in Japan. ^°^ Several other species of small 
importance affect numerous hosts. 



Podosphaera Kunze (p. 175) 

Perithecia globose or globose-depressed; ascus solitary, sub- 
globose, 8-spored; appendages equatorial or apical, dark-brown 
or colorless, dichotomously branched at the apex, branches simple 



THE FUNGI WHICH CAUSE PLANT DISEASE 183 

and straight or swollen and knob-shaped; appendages rarely of 
two kinds, one set apical, brown, rigid, unbranched or rarely 
1 to 2-times dichotomous at the apex, the other set basal, short, 
flexuous, frequently obsolete. 

Salmon recognizes four species; Engler and Prantl seven. 

P. oxyacanthae (D. C.) De Bary i«^' ^^^ 

Amphigenous; mycelium variable, persistent in thin patches 
or evanescent; perithecia scattered or more or less gregarious, 
subglobose, 64-90 /x; cells 10-18 /jl; appendages spreading more 





V 




/r?'; 




■•■*'V 


^i^ 


^ ...C!>. 


r/ 


. 1 


.^ 

l'*'*^.-- 


a 


/^ 




c 



Fici. loL'. — P. oxjarantlia'. ", piTithcciuni showing tlie apix'inlagcs with 
tips; 6, the one large ascus containing eight spores; c, the summer 
spore-form; d, a spore germinating in water. After Longyear. 

or less, equatorial, variable in number and length, from 4-30 in 
number and from 3^-6 or even 10-times the diameter of the 
perithecium, usually unequal in length, dark brown for more than 
half their length from the base, apex 2 to 4-times dichotomously 
branched, branches usually short and equal, ultimate branches 
rounded, swollen, and more or less knob-shaped, Fig. 133; ascus 
broadly obovate, or subglobose, 58-90 x 45-75 )u; spores 8, rarely 
6, 18-30 X 10-17 M- 

Conidia ( = Oidium cratsegi). 

Salmon finds the species very variable but cannot set aside as 
separate species P. tridactyla and P. myrtillina as is done by some 
authors. On some hosts perithecia are rare. It is thought that 
the mycelium remains alive over winter. 

Hosts: Amelanchier, Crataegus, Diospyros, Prunus, Pyrus, 



184 



THE FUNGI WHICH CAUSE PLANT DISEASE 




t h a e, appendage 
tips. After Sal- 
mon. 



Spirea and Vaccinium. Especially damaging to cherry and apple. 
Throughout the northern hemisphere. 

P. tridactyla (Wal.) De Bary is considered by Salmon ^^° as a 
variety of the last species. Hosts: Plum and 
other species of Prunus and of Spirea. 

Similar to the preceding in habit and general 
character but differing in more critical charac- 
ters. Perithecia 70-105 ix; cells 10-15 m; ap- 
FiG. 133.— P. oxycan- pendages 2-8 usually 4, 1 to 8-times the 
diameter of the perithecium, apical in origin, 
more or less erect, apically 3-5 or 6-times 
dichotomously branched, primary branches usually more or less 
elongate, sometimes slightly recurved; asci globose or subglobose, 
60-78 X 60-70 m; spores 8, 20-30 x 13-15 m- 

Chiefly European but found also in Asia and America. 
P. leucotricha (E. & E.) Salm. 

Mycelium amphigenous, persistent, thin, effused; perithecia 
densely gregarious, rarely more or less scattered, 75-96 /x, sub- 
globose, cells 10-16 m; appendages of two kinds, one set apical 
the other basal; apical appendages 3-11 in number, more or less 
widely spreading, or erect-fasciculate, 4 to 7-times the diameter 
of the perithecium, apex undivided and blunt or rarely once or 
twice dichotomously branched, brown basally; basal appendages 
nearly obsolete or well developed, short, tor- 
tuous, pale brown, simple or irregularly branched; 
ascus oblong to subglobose, 55-70 x 44-50 n, 
spores 22-26 x 12-14 fx, crowded in the ascus. 

Conidia ( = Oidium farinosum): elhpsoid, trun- 
cate, hyaline, 28-30 x 12 ^u. 

Primarily American but occurring in Europe 
and Japan. A most serious pest of the apple. 
This and P. oxyacanthae, the apple mildews of 
America, have been variously treated by writers ^^cotrtch^ 
so that the literature presents an almost inex- 
tricable tangle as has been pointed out by Pam- 
mel ^^^ and by Stewart, ^^^ Podosphsera oxyacanthae being fre- 
quently reported instead of P. leucotricha. Sphserotheca mali 
and Podosphsera oxyacanthae have also been much confused, due 




leu- 
ap- 
pend a g e tips. 
After Salmon. 



THE FUNGI WHICH CAUSE PLANT DISEASE 185 

to similarity of habit and the frequent abnormal development 
of the appendages, so that the published references are not always 
reliable. 



Microsphaera Levielle (p. 175) 

Perithecia globose to subglobose; asci several, 2 to 8-spored; 
appendages not interwoven with the mycelium, branched in a 
definite manner at the apex, usually dichotomously and often 
very ornately, rarely undivided or merely once dichotomous. 

According to Salmon there are thirteen species; Engler and 
Prantl recognize thirty. 

M. grossulariae (Wal.) Lev. 

Epiphyllous or amphigenous; mycelium evanescent or sub- 
persistent; perithecia scattered or densely aggregated, globose- 
depressed, 65-130 n; cells 14-20 n; 
appendages 5-22, colorless, 1-1 M 
times the diameter of the perithe- 
cium, 4 to 5-times closely dichoto- 
mously branched, branches of first 
and second order very short, all fiq. 135.— m. grossuiari^B, append- 
segments deeply divided, tips not age tips. After Salmon, 

recurved; asci 4-10, broadly ovate or oblong, usually with a very 
short stalk, 46-62 x 28-38 fx; spores 4-6, rarely 3, 20-28 x 
12-16 fx. 

On five species of Ribes and two of Sambucus. This is the 
common European gooseberry-mildew, which is not common in 
America except on the elder. 

M. berberidis (D. C.) Lev. occurs on the barberry in Europe 
and Asia. 

M. alni (Wal.) Salm. 

Amphigenous; mycelium evanescent or persistent; perithecia 
scattered to gregarious, globose-depressed, very variable in size, 
usually small, 66-110 /x, or even up to 135 ix; cells 10-15 n 
wide; appendages variable in number (4-26) and length, ^/s to 
2}/^ times the diameter of the perithecium, more or less rigid, 
colorless throughout or amber-brown at base, apex variously 





186 THE FUNGI WHICH CAUSE PLANT DISEASE 

(but not always) more or less closely 3 to 6-times dichotomously 
branched, tips of ultimate branches regularly and distinctly re- 
curved; asci 3-8, ovats to ovate-globose, 42-70 x 32-50 m, usually 

but not always short stalked; 4 to 
^^^0^^ 8-spored; spores 18-23 x 10-12 /z. 
"^ This species is the most variable of 

the Erysiphese showing large latitude in 
number of spores in the ascus, in length, 
color and branching of appendages, in 
Fig. 136.— m. alni, appendage size of perithecia. It occurs upon very 

tips. After Salmon. i ^ mi 

numerous hosts. Ihe economic ones on 
which it is most common are: Syringa, Lonicera, Alnus, Betula, 
Quercus, Carya, Castanea, Juglans, Platanus. 

It is confined to the northern hemisphere. 

Salmon recognizes in addition to the typical form six varieties. 
Those of economic importance are: 

(a) extensa (C. & P.) Salm., a robust form on various American 
species of oaks; 

(b) calocladophora (Atk.) Salm., also a robust form on American 
oaks but having pseudo-trichotomously branched appendages 
and large spores; 

(c) vaccinii (Schw.) Salm., in America on Catalpa and various 
genera of Ericaceae is a small-spored, long-appendaged form. It 
includes M elevata on Catalpa; 

(d) lonicerae (D. C.) Salm., on species of Lonicera in Europe. 
M. diffusa C. & P. 

Amphigenous; mycelium persistent, thin and effused, or sub- 
persistent and forming vague patches, or quite evanescent; peri- 
thecia scattered or gregarious, globose-depressed, very variable in 
size, 55-126 n in diameter, averaging 90-100 n, cells 10-20 fx 
wide; appendages very variable in number and length, 4-30, or 
rarely crowded and as many as 50, IJ^ to 7-times the diameter of 
the perithecium, smooth, aseptate or 1 to 3-septate in the lower half, 
colorless or pale brown towards the base, flaccid when long, thin- 
walled above, becoming thick-walled towards the base, apex 3 to 5- 
times dichotomously or subdichotomously divided, branching dif- 
fuse and irregular, branches of the higher orders sub-nodulose, 
often apparently lateral, tips of ultimate branches not recurved; 



THE FUxXGI WHICH CAUSE PLANT DISEASE 187 

asci 4-9, 48-60 x 28-30 At, ovate-oblong with a very short stalk; 
spores 3-6, usually 4, 18-22 x 9-11. 

Hosts: Desmodium, Glycyrrhiza, Lespecleza, Phaseolus, Sym- 
phoricarpos. 

M. betae Vanha ^^^ has recently been described as a species in- 
jurious to the beet. It is said to resemble E. polygoni but that 
cross inoculation between the beet and clover could not be made. 

M. ferruginea Erik, is found on cultivated Verbenas ^^^ in 
Sweden. 

M. euphorbiae (Pk.) B. & C. occurs on various hosts in America 
and Asia, including Astragalus, Colutea, Cuphea and Euphorbia. 
Its only economic importance is as the cause of a disease of the 
roselle and cowpea ^^^ on which it is very common. 

Amphigenous; mycelium usually subgeniculate; perithecia gre- 
garious in floccose patches or scattered, 85-145 n, rarely 180 n, 
cells 10-15 jjl; appendages 7-28, usually narrow, more or less 
flexuose and nodose, 2.5 to 8 times the diameter of the perithecium, 
colorless above, 3 to 4-times dichotomously branched, branching 
irregular and lax; asci 4-13, rarely up to 26, ovate or ovate-oblong, 
short-stalked, 48-66 x 26-35 fj.; spores usually 4, rarely 3, 5 or 6, 
16-21 X 10-12 fjL. 

Phyllactinia Leveille (p. 175) 

Perithecia large, globose-depressed to lenticular; asci many, 2 
or 3-spored; appendages equatorial, rigid, acicular, with a bul- 
bous base; apex of perithecium with a mass of densely crowded 
branched outgrowths. 

Typical epidermal haustoria are not produced but the mycelium 
sends special branches through the stomata into the intercellular 
spaces of the leaf.^^^ These branches attain some length and con- 
stitute a limited internal mycelium, a character that is considered 
by some as of sufficient importance to set the genus apart in a 
separate family. The internal mycelium gives off haustoria which 
penetrate cells of the mesophyll. The appendages exhibit strik- 
ing hygroscopic movements and aid in dissemination. 

Only one species is recognized by Salmon. 

P. corylea (Pers.) Karst. 

Hypophyllous or rarely amphigenous; mycelium evanescent 



188 THE FUNGI WHICH CAUSE PLANT DISEASE 

or more or less persistent; perithecia usually scattered, rarely 
gregarious, 140-270 n, rarely up to 350 n; cells rather obscure, 
15-20 fx; the apical outgrowth becomes mucilaginous attaching 
the perithecium firmly to places where it may fall; appendages 




Fig. 137. — Phyllactinia corylea. 1. Natural size, on 
chestnut leaf. 2. Perithecium enlarged. 3. Two asci. 
4. Three spores. 5. Conidia-bearing hyphae. 6. Co- 
nidium germinating. After Anderson. 

5-18, equatorial, 1 to 3-times the diameter of the perithecium; 
asci 5-45, subcylindric to ovate-oblong, 60-105 x 25-40 /x, more 
or less stalked, 2, rarely 3-spored; spores 30-42 x 16-25 fi. 

Conidia (=Ovulariopsis) acrogenous, solitary, hyaline, sub- 
clavate. 

On Magnolia, Liriodendron, Berberis, Xanthoxylum, Ilex, Celas- 
trus, Acer, Desmodium, Crataegus, Heuchera, Ribes, Hamamelis, 
Fraxinus, Asclepias, Catalpa, Cornus, Ulmus, Betula, Alnus, Cory- 
lus, Ostrya, Carpinus, Quercus, Castanea, Fagus and Typha. 



THE FUNGI WHICH CAUSE PLANT DISEASE 189 



Perisporiaceae (p. 170) 

Aerial mycelium covering the substratum with a dark growth, 
rarely absent, usually astromate. Perithecia on the mycelial threads 
or on a stroma, black, more or less globose, without opening or 
appendages, although in some genera (Meliola, etc.) mycelial out- 
growths from the base of the perithecium simulate appendages. 
Asci elongate, numerous; spores various; paraphyses none. 

Chiefly parasites, although several genera are saprophytes. 
About three hundred species. 

Aside from ascospores, in some species conidia of one or several 
forms are known. These may be borne in pycnidia or uncovered 
on hyphae. Apiosporium is especially rich in the number of its 
conidial forms. 

Key to Genera of Perisporiaceae 
Spores 1-celled 
Spores not curved 

Spores hyaline 1. Anixia. 

Spores brownish 2. Orbicula. 

Spores curved, green 3. Pseudomeliola. 

Spores 2-celled 
Spores, at least when immature, ap- 

pendaged 4. Zopfiella. 

Spores not appcndaged 

Perithecia borne on the aerial mycelium 
Spores not enlarging after maturity 
Spores smooth 
Aerial mycelium prominent. ... 5. Dimerosporium,p. 191. 
Aerial mycelium none, or poorly 
developed 
Asci cylindric-clavate ; para- 
sites 6. Parodiella. 

Asci saccate, large; sapro- 
phytes 7. Zopfia. 

Spores finely echinulate 8. Marchaliella. 

Spores enlarging after maturity ... 9. Richonia. 
Perithecia borne on a hairy stroma. ... 10. Lasiobotrys, p. 191. 
Spores 3 or more celled 

Aerial mycelium none or poorly developed 



190 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Spores with cross walls only 
Spores elongate to cylindric 

Spores 4-celled, saprophytes 11. Perisporium. 

Spores 4 to 8-celled; parasites. ... 12. Schenckiella. 

Spores needle-formed 13. Hyaloderma. 

Spores muriform 

Spores brown 14. Cleistotheca. 

Spores hyaline 15. Saccardia. 

Aerial mycelium prominent 
Spores with cross walls only 
Spores hyaline 

Saprophytic 16. Scorias. 

Parasitic 17. Zukalia, p. 191. 

Spores brown 

Perithecia without apparent ap- 
pendages 
Perithecia rounded, opening 

irregularly 18. Antennaria, p. 192. 

Perithecia elongate, clavate, 

opening by regular slits. . 19. Apiosporium, p. 191. 
Perithecia appearing to have 
appendages 

Stromatic 20. Limacinia, p. 193. 

Not stromatic 21. Meliola, p. 193. 

(Some species of Meliola have muri- 
form spores) 
Spores muriform 
Spores with an appendage at each 

end 22. Ceratocarpia. 

Spores not appendaged 

Subicle crustose 23. Capnodium, p. 192. 

Subicle radiate 24. Pleomeliola, p. 193. 



The genera of interest as pathogens induce disease rather by- 
covering, shading and smothering leaves with dense sooty-black 
coatings than by parasitizing their hosts. They are not strictly 
speaking parasites but live saprophytically upon the surfaces of 
leaves, fruit and twigs often subsisting upon insects or insect 
exudations, the so called "honey dew." 



THE FUNGI WHICH CAUSE PLANT DISEASE 191 

Dimerosporium Fuckel (p. 189) 

Perithecia depressed-globose, membrano-carbonous; asci clavate 
to ovate, 8-spored; spores 2-celled, hyaline or brownish; mycelium 
abundant, dark, forming a film and often bearing conidia on 
conidiophores. 

D. mangiferum Sacc. does some harm to the mango. 

D. pulchrum, Sacc. grows upon the leaves of several woody 
plants, such as privet, Lonicera, Carpinus and 
Cornus. Conidia=Sarcinella heterospora. 

D. collinsii (Schw.) Thiim., forms witches ^ "^ ^^S 
brooms on the service berry. 




Lasiobotrys Kunze (p, 189) 

Fig. 138. — Dimerospo- 

Perithecia superficial, globose, minute, JonidTife^ascu^: 
black, aggregated in botryose fashion, stro- ^^^^^ Winter. 
mate; asci cylindric, 8-spored; spores oblong, 2-celled, hyaline. 

The one species L. lonicerae Kze. forms dark coatings on honey- 
suckle leaves in Europe, North Africa and Siberia but does little 
or no harm. 

Zukalia Saccardo (p. 190) 

This genus is like Meliola except in its hyaline spores and in 
its perithecium. 

Z. stuhlmanniana is on seedling cocoanuts and other palms. 

Apiosporium Kunze (p. 190) 

Perithecia superficial, minute, globose to pyriform, membra- 
nous or carbonous; asci ovate to clavate, 8-spored; spores 
globose to oblong, hyaline; paraphyses none. Conidia=Torula, 
Fumago, Chaetophoma, etc. 

Several forms are known to constitute sooty coatings on leaves 
of woody plants, subsisting on insect secretions. The specific 
limitations in the genus have not been satisfactorily worked out 
owing to the comparative rarity of the ascigerous stages. 

A. salicinum. (Pers.) Kze. is common on leaves of many species 
of woody plants. 

Perithecia brownish, gregarious, globoid-oblong, composed of 



192 



THE FUNGI WHICH CAUSE PLANT DISEASE 



minute cells as in the Erysiphacese; spores ovate, guttulate, hyaline, 
10 X 8 m; conidia of various kinds, formed from the bases of the 
perithecia, (a) multicellular macroconidia, (b) unicellular micro- 
conidia, (c) gemmae. 

A. brasiliense Noack is reported on grape ^^^ in Brazil. 

Various species also occur on numerous woody and herbaceous 
plants which are infected with aphids or upon which their "honey 
dew" falls. 

Antennaria Link differs but little from Apiosporium. 

A. pithyophila Nees. occurs on leaves of fir; A. elaeophila Mont. 




Fig. 139. — ^Apiosporium salicinum. After Anderson. 

on the Olive; A. setosa Zimm. on coffee; A. footi B. & D. com- 
monly on green house plants; A. piniphilum Fcl. on fir. 

Capnodium Mont. (p. 190) 

This is easily distinguished from genera of similar habit by its 
muriform spores. 

C. quercinum Pers. occurs on oak; C. taxi S. & R. on Taxus; 
C. foedum Sacc. on Oleander; C. coffeae Del. on coffee; C. tiliae 



THE FUNGI WHICH CAU8E PLANT DISEASE 



193 



Fcl. on Tilia; C. citri B. & P. on leaves of citrus fruits in Europe 
and America. 

C. stellatum Bern, and C. guajavae Bern, cause sooty mold 
on various trees in the tropics; '^'^'^ C. corticolum McAlp. on citrous 
trees in New South Wales ^^^ and Australia; C. javanicum Zimm., 
on coffee. ^^^ C. meridionale Arnaud is on Oleander, oak, and 
olive, in Europe; ^^" C. olea Arnaud ^^^ on olive in France. 

Limacinia tangensis P. Henn. is on the mango and cocoanut in 
Africa. 

Pleomeliola hyphaenes P. Henn. is on leaves of Hyphaene in 
Africa. 

Meliola Fries (p. 190) 

Perithecia globose, surroimded by dichotomously branched 
hyphae which resemble the appendages of the Erysiphacese; asci 
short, broad, 2 to 8-spored; 
spores oblong, 2 to 5-septate, 
rarely muriform; paraphyses 
none. 

This is a genus of over one 
hundred thirty species, whose 
mycelium grows superficially 
upon leaves and twigs. 

M. camelliae (Catt.) Sacc. oc- 
curs on Camellia. 

Mycelium, copious, black, 
bearing various sporing bodies; 
perithecia black, spherical, 80- 
150 n., containing several 8- 
spored asci; spores 16-18 x 45 fi, 
olivaceous, 4-celled. Stylo- 
spores ovoid, 5 ix, hyaline, borne 
in flask-shaped pycnidia which 
may be as much as 1 or 2 mm. 
high; pycnidia globose resem- 
bling the perithecia but smaller, 
containing spherical spores of about the same size as the stylo- 
spores. Chlamydospores are also formed by the breaking up of 




Fig. 140. — M. camelliae. 3, pypnidium 
and spores. 4, other form of pyc- 
nidium. 5, perithecium, ascus and as- 
cospores. After Webber. 



194 THE FUNGI WHICH CAUSE PLANT DISEASE 

the mycelium. Fumago camellise Catt. is a conidial form of this 
species. 

M. penzigi Sacc.^^^'^^^ is found on Citrus forming a sooty black 
mold. It subsists on "honey dew," following principally certain 
insects as Aleyrodes, Ceraplastes, Dactylopius, and Aphis. The 
species is quite similar to the preceding. 

The hyphse are from olive-green to dark brown and when old 
are connected into a compact membrane. The fungus is entirely 
superficial, possessing, however, small knob-like projections for 
attachment and large discs (hyphopodia). Reproduction is by 
conidia, pycnidia, stylospores and perithecia. 

Webber says: 

"Several forms of conidia are produced, some being but slight 
modifications of the common cells of the mycelium, while others 
are compound spores. Pycnidia are small, spherical black repro- 
ductive bodies, about 40 /x in diameter, and are usually present 
in considerable numbers in the mycelium. They may be readily 
seen with a strong magnifying hand lens, but cannot be definitely 
distinguished from perithecia or the young stages of the stylospores. 
Stylospores are borne in conceptacles, which in their simplest form 
resemble flasks with long drawn-out necks. Frequently, however, 
they are much branched, and as they project from 1 to 2 mm. be- 
yond the mycelium they form quite a conspicuous part of the 
fungus. They are easily recognized with the unaided eye, and can 
be seen with considerable distinctness with a hand lens. Perithecia 
are black, spherical reproductive bodies closely resembling pycnidia, 
from which they can not be distinguished with a hand lens. How- 
ever, they are larger, being eighty micro millimeters in diameter. 
Each perithecium contains several asci and each of these bears 
eight ascospores. Some of the investigators who have studied 
this disease have failed to find perithecia, and only twice has the 
writer found them in his examination of material from Florida. 

"The various reproductive bodies other than perithecia, partic- 
ularly the conidia and stylospores, are developed in great abun- 
dance." 

M. niessleanea Wint. is common on Rhododendron. 

Several entomogenous fungi i i^*i '^ have been found which by prey- 
ing upon those insects which secrete honey dew, lessen the injury 



THE FUNGI WHICH CAUSE PLANT DISEASE 195 

from all sooty molds. Among these are the genera Aschersonia^^^ 
and Sphaerostilbe. 

Microthyriaceae (p. 170) 

Mycelium superficial, dark; perithecia superficial, separate, 
shield-shaped, unappendaged, black, membranous to carbonous, 
formed of radiating chains of cells; asci 4 to 8-spored, short; pa- 
raphyses usually present, 

A family of over twenty genera and more than three hundred 
species, chiefly poorly understood. 

Only two species have been noted as serious economic patho- 
gens; Scolecopeltis aeruginea Zimm, and Microthyrium coffae 
both on coffee in Africa. 

The genera of the Ascomycetes which remain to be treated, 
and which are separated from those preceding by the possession 
of an ostiole, are by some known under the name Pyrenomycetes. 
Cf. p. 170. There are three orders, the Hypocreales, Dothidiales 
and Sphseriales. 

Hypocreales (p. 124) 

The chief character separating this order from other Pyrenomy- 
cetes is the brighter color — yellow, purple, scarlet, red, etc. — and 
the more tender texture of its perithecia, — soft, fleshy, cottony, 
patellate or effused. 

The perithecium also differs from that of the preceding orders in 
the possession of a distinct opening, ostiole, for the exit of spores. 

Perithecia globose to cylindric or flask-shaped, free on the sub- 
stratum (rarely subepidermal) or united by a common matrix, 
which varies from a cottony subiculum to a distinct fleshy stroma, 
wall membranous or at least not truly carbonous; asci cylindric, 
clavate or subovoid, mostly 4 to 8-spored but often becoming 
16-spored by the separation of each original spore into two globose 
or subglobose cells; spores simple or compound, hyaline or colored, 
globose to filiform. 

Conidia are usually produced freely, each genus usually possess- 
ing at least one form of free-borne conidia, while in some genera 
several diflferent kinds of conidia are found. Pycnidia are rare. 
Often the ascigerous stage is nearly suppressed and rare while 
one or more of the conidial forms predominates. 



196 THE FUNGI WHICH CAUSE PLANT DISEASE 

Such form genera as Verticillium, Tubercularia, Sphacelia, 
Sphaerostilbe and Isaria are connected with the Hypocreales. 

The order includes some sixty genera, and over eight hundred 
species. Of these only a half dozen genera contain important plant 
parasites, another half dozen genera, parasites of less importance. 
The rest are saprophytes, insect parasites, etc., of no economic 
significance. 

Opinion differs as to the characters which should be made the 
basis for subdivision of this family, whether to throw main stress 
upon the structure of the perithecium or upon the character of 
the spores. 

Following Lindau the order contains a single family, Hypo- 
creaceae,^^^"^^^ which may be divided into six subfamilies. Accord- 
ing to a more recent treatment of the American members of the 
group by Seaver ' two families and four tribes are recognized. 
Lindau's tribes Hyponectrieae, Hypomycetese, and Melanosporeae 
are united with a part of Nectriese under the last name while the 
remaining genera, referred by Lindau to this tribe, constitute the 
tribe Creonectrese, These tribes constitute the family Nectriaceae. 
The remaining tribes, Hypocreese and Clavicipitese with about the 
same limits constitute the family Hypocreacese. 



Key to Tribes of Hypocreaceae 

Perithecia at first sunken in the substratum, 

later erumpent 1. Hyponectrieae. 

Perithecia not sunken in the substratum; 
stroma present or absent 
Stroma cottony, never fleshy; perithecia 
immersed in the stroma, or borne on 

its surface 2. Hypomyceteae. 

Stroma fleshy or wanting 

Spores dark colored; perithecia free on 
the substratum (in some species 
of Melanospora with a cottony . 

stroma) scattered 3. Melanosporeae. 

Spores hyaline, yellow or red 

Perithecia without a stroma, or on a 

fleshy stroma 4. Nectrieae, p. 197. 



THE FUNGI WHICH CAUSE PLANT DISEASE 197 

Perithecia sunken in a fleshy stroma 

Spores not filiform ; perithecia half 
or entirely sunken in the 
stroma, and distinct from it. . 5. Hypocreeae, {). 198. 

Spores filiform; perithecia com- 
pletely embedded in the 
stroma and not clearly dis- 
tinct from it 6. Clavicipiteae, p. 199. 

The first tribe contains no parasitic genera while the second and 
third contain but one each. Of the Hypomycetese, the genus 
Hypomyces (p. 200) is set off from the others by its 2-celled hyaline 
fusiform spores, and its cottony stroma. Of the Melanosporeae 
the genus Melanospora (p. 200) is distinguished by the long beaks 
of its flask-shaped perithecia, which are brown rather than black, 
and its brown 2-celled spores. 

Keys to the Genera of Nectrieae, Hypocreeae and Clavicipiteae 

Tribe IV. Nectrieae (p. 196) 

Conidiophores not of the Stilbum tj^pe 
Spores elongate, 1-celled; perithecia free 
on the substratum; stroma none 
Spores not appendaged 
Perithecia yellow or red 
Asci cylindric; ostiole concolorous 

with the perithccium 1. Nectriella. 

Asci clavate-cylindric; ostiole 

darker than the perithecium.. 2. Thelocarpon. 

Perithecia violet or blue 3. Lisiella. 

Spores appendiculate 4. Eleutheromyces. 

Spores elongate, 2 to many-celled 
Spores with cross walls only 
Spores 2-celled 
Asci 8-spored; often with 1-celled, 
conidia formed in the ascus 
Perithecium yellow or red 

Spores hyaline 5. Nectria, p. 201. 

Spores brown 6. Neocosmospora, p. 205. 

Perithecium blue or violet 7. Lisea. 



198 THE FUNGI WHICH CAUSE PLANT DISEASE 

Asci many-spored 

Perithecium fleshy, ostiole ele- 
vated 8. Metanectria. 

Perithecium hard, ostiole sunken 9. Cyanocephalium. 
Spores 2 to many-celled 
Spores not appendiculate 

Perithecium bright colored, not 

blue 10. Calonectria, p. 205. 

Perithecium blue or violet 11. Gibberella, p. 206. 

Spores appendiculate, 4-celled 
Perithecia clavate, ostiole wart- 
like 12. Paranectria. 

Perithecia flask-shaped, ostiole 

elongate 13. Lecythium. 

Spores muriform 

Perithecium bright colored, not 

blue 14. Pleonectria, p. 207. 

Perithecia dark colored or blue. . . 15. Pleogibberella. 
Spores filiform 

Perithecia fleshy, bright colored 16. Ophionectria, p. 207. 

Perithecia horny, brown 17. Barya. 

Conidiophores of the Stilbum type, stroma 
wanting 

Spores 2-celled 18. Sphaerostilbe, p. 207. 

Spores 4-celled 19. Stilbonectria. 

Spores muriform 20. Megalonectria. 

Tribe V. Hypocreeae (p. 197) 

Stroma sunken in the substratum or grown 
to it, usually free later 

Spores 1-celled 21. Polystigma, p. 207. 

Spores 2-celled 22. Valsonectria, p. 208. 

Spores several-celled by cross walls 23. Cesatiella. 

Spores muriform 

Spores hyaline 24. Thyronectria. 

Spores olive-brown 25. Mattirolia. 

Stroma from the first separable from the 
substratum 

Spores 1-celled 26. Selinia. 

Spores 2-celled 

Cells of the spores separating in the ascus 



THE FUNGI WHICH CAUSE PLANT DISEASE 199 

Stroma patellate or effuse 27. Hypocrea, p. 209. 

Stroma erect, simple or branched. . . 28. Podocrea. 
Cells of the spores not separating in the 
ascus 

Stroma patellate or effuse 29. Hypocreopsis. 

Stroma erect, branched 30. Corallomyces. 

Spores 3 to many-celled 
Stroma bright or dark colored, not 

conidia-bearing 31. Broomella. 

Stroma dark, green or black, with 
conidia 

Conidia of two kinds 32. Loculistroma, p. 215. 

Secondary conidia absent 33. Aciculosporium, p. 211. 

Spores muriform 34. Uleomyces. 

Tribe VI. Clavicipiteae (p. 197) 
Stroma effused 

Stroma forming a sheath about the host. 35. Epichloe, p. 210. 
Stroma flat, tuberculate, or disk-shaped 
Stroma not conidia-bearing 

Stroma thick, usually light colored. . 36. Hypocrella. 

Stroma thin, black 37. Dothiochloe, p. 210. 

Stroma with the inner portion conidia- 
bearing 38. Echinodothis, p. 211. 

Stroma erect 

Stroma small, saccate, membranous 39. Oomyces. 

Stroma large, erect, with distinct sterile 

and fertile portions, the latter often 

knob-like 

Stroma formed in the bodies of insects 

and spiders, or in subterranean 

fungi 40. Cordyceps. 

Stroma formed in the inflorescence of 

Glumacea^, etc., spores continuous 

Stroma not growing from a sclero- 

tium 41. Balansia, p. 209. 

Stroma growing from a sclerotium 
after a period of rest 

Asci preceded by conidia 42. Claviceps, p. 211. 

Asci preceded by smut-like chla- | 43. Ustilaginoidea, p. 213. 
mydospores I 44. Ustilaginoidella,p.ll4. 



200 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Hypomyces Fries (p. 197) 

Stroma an effused cottony subiculum, often of considerable 
extent; perithecia numerous, usually thickly scattered and im- 
mersed in the subiculum, rarely superficial; asci cylindric, 8-spored; 

spores fusoid or fusiform, 
usually apiculate, rarely 
blunt, 2-celled, hyaline; 
conidial phase variable. 

This genus of some forty 
species contains but few 
saprophytes, the majority 
being parasitic, chiefly on 
the larger fungi. The genus 
is of economic interest only 
as affecting mushrooms, 
though one species, H. 
hyacinthi has been found 
causing secondary infec- 
tion in onions, following 
a bacterial trouble, and 
another; H. solani Reinke 
follows a similar disease 
on potatoes. Chlamydospores and conidiospores develop, be- 
longing to various form genera as Verticillium, Mycogone, Fuligo, 
Diplocladium, Dictylium, Sepedonium, Blastotrichum. 

Allied to this genus are probably Mycogone rosea and M. per- 
niciosa) which are destructive enemies of mushroom culture. 




C 

Fig. 141. — Hypomyces ochraceus. B, peri 
thecia; C, asoi and spores; D, spores; E, co 
nidia; F, chlamydospores. After Tulasne. 



Melanospora Corda (p. 197) 

Perithecia superficial, without a stroma, globose-pyriform or 
flask-shaped, with a long neck which is usually clothed at the 
tip with a fringe of hairs, perithecia often hairy; asci broadly 
clavate, 4 to 8-spored; spores 1-celled, brown to brownish-black. 

The genus contains some forty species, mostly common 
saprophytes. 

M. damnosa (Sacc.) Lin. is serious on wheat and rye.^-^' ^^^ 



THE FUNGI WHICH CAUSE PLANT DISEASE 



201 



M. stysanophora Mat. is said to be an ascigerous stage of 
Dematophora glomerata, cf. p. 230, so injurious to the grape. 



Nectria Fries (p. 197) 

Stroma absent or tubercular, fleshy, bright colored; perithecia 
single, or gregarious, on or in the stroma or among cottony hyphse, 
globose or ovate, walls fleshy, yellow, red or brown, smooth or 
hairy; ostiole papillate or not; asci cylindric or clavate, 8-spored; 
spores elongate blunt or pointed, 
hyaline, rarely red, 2-celled, form- 
ing conidia in the ascus; paraphyses 
usually none. 

As conidial stages occur the form 
genera Cephalosporium, Tubercu- 
laria, Fusarium, Spicaria, Fusidium 
and Chsetostroma. Much doubt 
exists as to specific limitations, and 
as to the life histories of the species. 
Some two hundred fifty species have 
been described. Several are cred- 
ited with causing serious diseases, 
most of them occurring as wound parasites and unable to effect 
entrance into sound tissue. Other species are pure saprophytes 
and harmless. 

The genus Nectria is divided into seven sub-genera, which are 
frequently given generic rank, as follows : 




Fi 



142. — Melanospora. K, peri- 
thecium ; L, asci ; M, spores. After 
Lindau. 



Key to Subgenera of Nectria 

Spores smooth 
Perithecia smooth 

Stroma fleshy 1. Eunectria, p. 202. 

Stroma a cottony subiculum 2. Hyphonectria. 

Stroma usually absent; perithecia 

scattered 3. Dialonectria, p. 205. 

Perithecia hairy 4. Lasionectria. 

Perithecia scaly 5. Lepidonectria. 

Spores tuberculate 6. Cosmonectria. 

Spores appearing striated, golden brown ... 7. Phaeonectria. 



202 



THE FUNGI WHICH CAUSE PLANT DISEASE 



The majority of economic species belong to the first subgenus. 

Eunectria (p. 201) 

N. cinnabarina (Tode) Fr. 

Stroma erumpent, tubercular, at first pinkish or yellowish-red, 
darker with age, 1-2 mm. high and broad; perithecia almost glo- 
bose, the ostiole rather prominent, becoming slightly collapsed, at 
first bright cinnabar-red, darker with age, granular, 375-400 n 
in diameter; asci clavate, 50-90 x 7-12 m; spores mostly 2-seriate, 

elliptic elongate, ends obtuse, 
slightly curved, 12-20 x 4-6 n; 
paraphyses delicate. 

Tubercularia vulgaris borne on 
the stroma is the conidial stage. 
Conidiophores aggregated into tu- 
bercular masses each 50-100 ju long; 
conidia on short lateral branches, 
elliptic, hyaline, 4-6 x 2 /x. 

The closely septate delicate 
hyphse grow rapidly through the 
wood or bark, penetrating nearly 
every cell and turning the wood 
After black and collecting to form stro- 
mata on or in the bark. These 
stromata in fall or spring break through the epidermis and produce 
warty, gray to pink, excrescences, which at first bear profuse 
conidia both terminally and laterally on short stalks and later 
dark-red ascigerous structures; though the latter are much less 
common and are often absent. The fungus is said to be unable to 
affect living cambium and cortex. 

It is found saprophytically on many decayed woody plants that 
have been frost killed, and parasitically on pear, Tilia, ^sculus, 
China berry, Betula, Ribes, Acer, Carya, Morus, Prunus, Quercus, 
Ulmus, etc. Mayer ^-^ germinated spores on a cut branch; the 
mycelium spread to and killed the main stem; tubercles appeared 
and during the following year perithecia developed on these 
tubercles. In America the species has attracted attention on the 
currant ^-^' ^^^ in which host the mycelium invades chiefly the 




Fig. 143. — N. cinnabarina, perithe- 
cia in stroma, ascospores issuing in 
cirri ; germinating spores 
Hartig. 



THE FUNGI WHICH CAUSE PLANT DISEASE 203 

cambium. On this host, however, it is now said to be non- 
parasitic.^'^ 

Durand,^^^ culturing the conidial form on sterile currant stems, 
observed the formation of tubercles with abundant conidia after 
about fourteen days. On agar conidia were produced directly from 
single hyphae without any stroma. Perithecia were found in the 
field on the tubercles with the conidia in February. 

N. ditissima Tul. 

Stroma light colored; perithecia cespitose, densely and irregu- 
larly clustered, or rarely scattered, ovate, ostiole prominent, bright 
red, smooth or roughened; asci cylindric to clavate, 80-90 x 8-10 m; 
spores fusoid, 12-16 x 4-5 fx. 

The unicellular microconidia are followed by falcate, multi- 
cellular, macroconidia (Fusidium candidum), which are borne on 
pale stromatic cushions. 

Common on dicotyledonous trees, especially beech, oak, hazel, 
ash, alder, maple, lime, apple and dogwood, where it is usually a 
wound parasite, particularly common after hail. It is especially 
well known from Europe and has more recently attracted atten- 
tion in America. 

The mycelium does not usually advance more then one centi- 
meter in each year. It is believed that it can travel within the 
wood and break through the cambium and cortex at points some 
distance from the place of original infection, thus producing new 
spots. Very minute conidia produced in the bark aid in tissue de- 
composition. White conidial (Fusidium) stromata appear near 
the periphery of affected spots and here, too, in groups or scattered, 
appear the deep red perithecia. 

N. cucurbitula Sacc. 

Perithecial clusters erumpent, often irregular in form, 1-2 mm. 
in diameter; perithecia densely clustered, bright red, ovate, with 
a prominent ostiole, rarely collapsing; asci cylindric to clavate 
75-100 X 6-8 fj.; spores at first crowded and partially 2-seriate, 
finally becoming 1-seriate, lying obliquely in the ascus, broad, 
fusoid, rarely subelliptic, 14-16 x 5-7 ju. 

Its hosts are spruce, fir, pine and other conifers in Europe and 
North America. 

The fungus is usually a wound parasite, often following hail. 




. 204 THE FUNGI WHICH CAUSE PLANT DISEASE 

Germ tubes from ascospores or conidia enter the cortex and 
develop a rich mycehum in the sieve tubes and soft host. This 
advances most rapidly during the dormant period of the bast. 

White or yellow stromata the size of a pin- 
head appear and bear numerous conidia. Later 
come the red perithecia whose ascospores ripen 
in winter or spring. 
N. ribis (Tode) Rab. 
Fig. 144.— n. ipo- Cespitose, stroma compact; perithecia sub- 

of p e'r i t h e c i a. globose, smooth ; ostiole papillate ; asci subclavate, 

After Halsted. gQ-lOO X 15; spores elongate or fusoid, hyaline, 
1-septate, 18-20 x 5-6 mm. On currant. 

N. ipomoeae Hals. 

Perithecia clustered, ovate, roughened, red; asci cyhndric- 
clavate; spores elliptic; conidial phase (Fusarium) appearing as a 
white mold-like covering of the host; conidia several-celled, falcate. 

Halsted ^-^ inoculated sterilized egg-plant stems with the Nectria 
spores and the Fusarium form developed, followed by the asci- 
gerous stage. Ascospores in hanging drop were also seen to give 
rise to the Fusarial stage. The Nectrias found upon egg-plant 
and sweet potato, morphologically alike, were proved by cross 
inoculations to be identical. 

N. rousselliana Tul. and N. pandani Tul. are parasitic on Buxus 
and Pandanus respectively, the former with the conidial stage. 
Volutella buxi. 

N. solani Ren. & Bert, is said by Massee to be the ascigerous 
form of Fusarium solani. 

Perithecia crowded on a stroma, minute, conic-globose, smooth, 
blood-red; asci clavate; spores hyaline, 8-9 x ^. 

5 fx; paraphyses slender, tips strongly clavate. W^f \Ji 

Conidia ( = Fusarium solani) hyaline, 3 to // L i 
5-septate, fusiform, 15-40 x 5-8 /x, but very u"^ |] I // 
variable, borne on erect, simple or branched Fig. 145. — N. ipo- 
conidiophores. ^Zkllt. A^to 

N. coffeicola Zimm. is on cacao and vanilla; Halsted. 
N. bainii Mas. N. amerunensis A. & Str. and N. diversispora 
Petch. are reported parasitic on cacao ^^^ pods. The three latter 
names are probably synonyms of the first. 




THE FUNGI WHICH CAUSE PLANT DISEASE 205 

N. vandae Wah. and N. goroshankiniana (Wah.) grow on cul- 
tivated \'anda: N. theobromae Mass., probably identical with 
N. striatospora Zimm., is found on cacao trunks as is also N. jun- 
geri Henn. 

N. bulbicola. Henn. is on orchids and N. gigantispora Zimm. on 
Ficus. 

Dialonectria (p. 201) 

N. graminicola B. & B., the conidial stage of which is Fusarium 
nivale is destructive to winter wheat and rye 
in Europe.^^^ 

Less known are N. bogoriensis Bern and 
N. vanillas Zimm. on vanilla; N. luteopilosa 
Zimm. and N. fruticola Zimm. on coffee; ^^^ 
N. theobromicola Mass. on Theobroma. 

Neocosmospora E. F. Smith was reported by 
Smith ^^^ as the ascigerous form of Fusarium -pia. 146.— N. ipo- 
vasinfectum and consequently as the cause of moese, an aseus. 

^ "^ o,c, a, germination 

many serious wilt diseases. Recent work by of ascospores. Af- 
Higgins ^^^' ^^^ and by Butler ^^^ has shown 
that in all probability there is no genetic connection between 
these forms and that the fungus under discussion is merely a 
harmless saprophyte. 



Calonectiia (p. 198) 

Perithecia free, often closely gregarious, true stroma wanting 
but perithecia often surrounded by a radiate, white mycelium 
which may simulate a stroma; perithecia globose to ovate, red 
or yellow; asci elongate, 8-spored; spores elongate, more than 
2-celled. About sixty species. 

C. p3rrochroa (Desm.) Sacc, has been reported parasitic on 
Platanus. ^ Its conidial stage is Fusarium platani. 

C. flavida Mass. is in the West Indies on cacao causing 
canker. 

C. cremea Zimm. with Spicaria colorans, Corymbomyces albus, 



206 THE FUNGI WHICH CAUSE PLANT DISEASE 

Clanostachys theobromse ^^^ probably as its conidial stages, is on 
fruits and stems of cacao. 

C. bahiensis Hem. reported in South America on cacao stems 
is really an Anthostomella; C. gigaspora Mass. is found on 
sugar-cane. 

Gibberella Saccardo (p. 198) 

Stromata tuberculate, more or less effused; perithecia cespitose 
or occasionally scattered on or surrounding the stroma; asci clavate, 
8-spored; spores fusoid, 4 to many-celled, hyaline; conidial phase 
a Fusarium. 

Of the thirteen species but few are parasitic. 
G. saubinetii (Durieu & Mont.) Sacc. ^^^' ^^^ 
Perithecia gregarious, leathery membranous, verrucose, ovate, 

subpedicellate, bluish, papillate, 
200-300 X 170-220 m; asci oblong 
clavate, acuminate, 60-76 x 10- 
12 ju; spores one or obhquely 
two-ranked, fusiform, curved or 
straight, acute, 4-celled, 18-24 x 
4-5 fi; mycelium effused, crus- 

FiG. 147.— G. saubinetii; 2, Fusarium tose, white to rose colored. Co- 
spores, 5, the asci. After Selby. / t-i 

nidia ( = Fusanum) solitary, or 
clustered, fusiform, curved, acute or apiculate, 5-septate, hyaline, 
24-40 X 5 /x. 

Many species of Fusarium, e. g., F. culmorum, F. avenaceum, 
F. hordei, F. heterosporum, have been referred to this ascigerous 
stage. Spherical stylospores are also reported. ^""^ 

The mycelium and the conidial stages often coat the grains and 
heads of cereals with red or pink. Perithecia are rare as shining 
dark dots on the grains in the late season. The Fusarium stage 
also is said to cause a clover and alfalfa disease and the fungus by 
inoculation and culture is shown to be identical on wheat, clover, 
barley, rye, spfelt, emmer, and oat. It is carried from season to 
season on infected seed and causes large loss of young plants. 
Doubt as to the relationship of the Fusarial forms mentioned with 
the ascigerous stages has been raised by the work of Appel and 
Wollenweber. See also Fusarium (p. 646). 




THE FUNGI WHICH CAUSE PLANT DISEASE 207 

G. cerealis Pass., the cause of a serious wheat disease in Italy '^^ 
may be identical with the last species. 

G. moricola Ces. & d. Not. grows on Morus. 

Pleonectria Saccardo (p. 198) 

Perithecia cespitose or separate, globose, pale, papillate; asci 
8-spored; spores many-septate, muriform, hyaline. 

P. berolinensis Sacc, which occurs on various species of 
wild and cultivated currants both in Europe and America has 
been reported by Durand ^^® as associated with a currant trouble 
in New York. 

P. coffeicola Zimm. attacks coffee. 

Ophionectria Saccardo (p. 198) 

Stroma globose, tubercular, depressed or none; perithecia su- 
perficial, clustered or scattered; asci cylindric to clavate, 2 to 
8-spored; spores 4 to many-celled, fusoid to subfiliform, hyaline 
or subhyaline. 

About fourteen species. O. coccicola E. & V. attacks scale in- 
sects and is said also to cause gummosis of oranges.^^* O. foliicola 
Zimm. is found on coffee. 

Sphaerostilbe Tulasne (p. 198) 

Stroma a slender stalk with a globose or conical head; perithecia 
bright colored, membranous, globose, subglobose or ovate; asci 
cylindric or subcylindric, 8-spored; spores 2-celled, elliptic or 
subelliptic, hyaline. Conidial phase Stilbum, Atractium or Micro- 
cera. 

Some twenty species. S. repens B. & Br. in India causes a 
root disease of Hevea^^^ and arrowroot. 

22 

S. flavida Mass. causes disease of coffee in tropical America. 

Polystigma De Candolle (p. 198) 

Stroma jQeshy, effused, red or reddish-brown, growing on leaves; 
perithecia sunken, only the ostiole being above the surface, thin, 
leathery, hyaline; asci elongate, clavate, 8-spored; spores ellipsoid, 
1-celled, hyaline. Three species. 



208 THE FUNGI WHICH CAUSE PLANT DISEASE 

P. ruba (Pers.) D. C. causes reddish spots on the leaves of 

#Prunus. Stroma at first bearing pycnidia 
A (Libertella rubra) with fiUform hooked, con- 
I 1 1 tinuous conidia. Perithecia produced on old 
^ " leaves, bearing ellipsoid to elongate asci; 
spores 10-13 x 6 ^i, smooth. 

The invaded leaf tissue is colored by the 
mycelium which bears a reddish oil. Nu- 
merous perithecia are immersed in the 
diseased area and, opening to the surface, 
extrude spores which seem incapable of in- 
fecting. During winter the stroma darkens, 
^ ^,„ „ , turns hard and produces the perithecia and 

Fig. 148. — P. rubrum. ^ . , • , ,., 

D, asci; E, conidia. ascosporcs. Ascogomum and trichogjoie-like 

organs have been described. ^^* 
P. ochraceum (Wahl.) Sacc. occurs on Prunus padus. 



Valsonectria Spegazzini (p. 198) 

Stroma thin, cushion-shaped, under the bark of the host; peri- 
thecia similar to those of Valsa, sunken in the stroma, the beak 
erumpent, red; asci cylindric, 8- 
spored; spores 2-ceIled, hyaline or 
light brown. 

A genus of but three species which 
differ from Valsa chiefly in their ]^ 
red color. ' ^ 

V. parasitica (Murr.) Rehm.^^^' ^^^' 

Pustules numerous, erumpent, at — ~ q -■;., 

first yellow, changing to brown at fig. 149— Shoeing a pycmdium of 

maturity; perithecia usually ten to Valsonectm and the manner in 
•^ ' ^ "^ which the j^porcs issue irom it. 

twenty in number, closely clustered. After MurriU. 
flask-shaped, deeply embedded in the stroma in the inner bark, 
scarcely visible to the unaided eye; necks long, slender, curved, 
with thick black walls and rather prominent ostiola; asci oblong- 
clavate, 45-50 x 9 m, 8-spored; spores usually biseriate, hyaline, 
oblong, rounded a,t the ends, often slightly constricted, unisep- 
tate, 9-10 X 4-5 /x- Summer spores very minute, 1 x 2-3 n, pale- 




THE FUNGI WHICH CAUSE PLANT DISEASE 



209 



yellowish, cylindrical, slightly curved, discharged in twisted threads 
as in Cytospora. 

This fungus, originally described as Diaporthe parasitica, is a 
serious parasite on the chestnut. The mycelium grows through 
the inner bark in all directions from the initial wound at which in- 
fection occurred, eventually girdling the part. The wood is also 
affected. The perithecia appear in abundance upon or in cracks 
of the bark, extruding their spores in greenish to yellow threads. 

Hypocrea Fries (p. 199) 

Stroma subglobose to patellate, fleshy or subfleshy; perithecia 
entirely immersed, subglobose to ovate, the necks slightly pro- 
truding; asci cylindric, originally 8-spored, spores breaking each 
into two so that the asci at maturity contain sixteen hyahne 
spores. About one hundred ten species. 

H. ceretriformis Berk, occurs on the bamboo in Tonkin; 

H. sacchari on sugar cane. 

Balansia Spegazzini (p. 199)^^^ 

Sclerotium composite, formed of the affected parts of the host 
embedded in a well developed mass of fungous tissue; stroma 
arising from the sclerotium, stipi- 
tate and capitate or sessile, pul- 
vinate, obovate, discoid, or sepa- 
rated from the sclerotium as 
soon as the latter is mature, sur- 
face slightly papillate from the 
projecting ostiola of the im- 
mersed scattered perithecia; asci 
8-spored; paraphyses none. Co- 
nidia, when known, an Ephelis 
and preceding the stroma. 

B. hypoxylon (Pk.) Atk. oc- 
curs on various grasses, chiefly 
in the southern United States. 
B. claviceps Speg. infests Setaria 
and Pennisetum in tropical lands. 
The remaining species, chiefly of warm regions, are mostly grass 
inhabiting. 




Fig. 150. — B. hypoxylon, section of 
pseudosclerotium and one stroma 
showing perithecia, stem, leaf ele- 
ments and an ascus. After Atkinson. 



210 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Dothichloe Atkinson (p. 199) ^^^ 

Stroma thin, hard when dry, black, especially the outer portion, 
lighter within, effuse, pulvinate, disciform or armilla-form, partly 
or entirely surrounding the host; perithecia crowded, confluent 
with the stroma, but the thin walls of distinctive structure, im- 
mersed, the apex projecting; asci cylindric, 8-spored; spores fili- 
form, septate at maturity, and eventually 
separating at the septa into short seg- 
ments. 

Like the preceding genus, both species 
D. atramentosa (B. & C.) Atk. 'and D. 
aristidae Atk. are grass inhabitors of 
warm regions of the United States. The 
former is the commoner species with a 
wider range of hosts. 

Epichloe (Fries) Tul. (p. 199) 

Stroma effused, subfleshy, at first pale, 
becoming bright orange, sheathing the 
host; perithecia immersed or with the 
ostiola protruding; asci cylindric, 8- 
spored; spores filiform, many-celled. Of 
some nine species only one is important. 
E. t3rphina (Pers.) Tul. Stroma ef- 
fused, at first pale, becoming bright 
orange, forming sheaths 2-5 cm. long 
Fig. 151.— Epichloe. ^, habit around stems of various grasses, often 
L'tf^rrb^'afcusT A^iTo? destroying the inflorescence; perithecia 
spore. After Winter, Bre- thickly scattered, partially or entirely im- 

feld and Lindau. i • i n, ^ 

mersed in the stroma, soft, membranous, 
concolorous with the stroma, the ostiole rather prominent; asci 
very long; spores almost as long as the ascus, closely fasciculate, 
multiseptate, about 2 /i in diameter; conidia elliptic, hyaline, 
4-5 X 3 M, preceding the perithecia on the stroma. 

Many grasses are affected, often to serious extent. The mycelium 
shows first as a yellowish cobwebby growth surrounding the leaf 
sheath and soon develops a conidial stroma. Later the stroma 




THE FUNGI WHICH CAUSE PLANT DISEASE 211 

turns to orange-color and the perithecia appear, forming a 
layer. 

Echinodothis Atkinson (p. 199) ^^^ 

Stromata subfleshy or corky, light-colored, pulvinate to sub- 
globose or irregular in form, often constricted at the base, some- 
times entirely surrounding the host, consisting of several layers of 
different consistency; perithecia superficial, scattered, subcylindric, 
sessile, giving an echinulate appearance to the stroma; asci cylin- 
dric, 8-spored; spores linear, septate, at length separating at the 
septa into short segments. 

Two species, parasitic on grasses in the warmer parts of the 
western hemisphere. 

E. tuberiformis (Berk. & Rav.) Atk.^^s 

Stromata subglobose, 1 cm. or more in diameter, entire, lobed, 
or divided, seated upon the reed or upon the leaf-sheath and fas- 
tened by a whitish mycelium consisting of radiating threads which 
are sometimes tinged yellowish-brown ; substance leathery or corky, 
consisting of three layers, an inner layer white to pinkish, an inter- 
mediate layer light ochraceous and an outer layer cinnamon; 
stroma externally dark brownish becoming black; conidiophores 
needle-shaped; conidia ovoid to fusoid, 3-4 x 7-10 n; perithecia 
entirely superficial in small clusters or evenly distributed over 
the exposed surface of the stroma, subconic in form, giving the 
whole stroma a spiny appearance, clothed except the apex with a 
dense covering of minute threads which are at first whitish, be- 
coming cinnamon colored, the naked apex becoming black, about 
0.3 X 1 mm. ; asci cylindric, with a swelUng at the apex, very large, 
475-750 x 14-20 /x; spores nearly as long as the ascus, hyaline or 
slightly yellowish, many-septate, the joints 15 x 4-5 n. 

On Arundinaria in the Southern States. 

Asciculosporium take Miy.^^^ forms witches' brooms on bamboo 
in Japan. It is closely related to Dusiella and Epichloe. 

Claviceps Tulasne (p. 199) 

Sclerotium formed within the hypertrophied tissues of the 
ovary of the host, succeeding the conidial stage which is a 
Sphacelia; stroma erect, with a long sterile base and a fertile. 



212 



THE FUNGI WHICH CAUSE PLANT DISEASE 



usually knot-like head; perithecia closely scattered, sunken in 
the stroma with only the ostiole protruding, flask-shaped, the 
walls scarcely distinguishable from the stroma; asci cylindric, 






^-0 

















Fig. 152. — C. purpurea. D, Sphacelia stage; E', germinated sclerotia; G, sec- 
tion of stroma; H, section of a perithecium; J, ascus with spores. After 
Tulasne. 

8-spored; spores hyaline, continuous. Some twelve or fifteen 
species are recorded all affecting the ovaries of the Graminese. 

C. purpurea (Fr.) Tul.^^^ 

Sclerotium elongate, more or less curved, and resembling a much 
enlarged grain, after a period of rest producing few or many, 
clustered or scattered stromata which are 0.5-1.5 cm. high; spore 



THE FUNGI WHICH CAUSE PLANT DISEASE 213 

60-70 fji. long. Conidia ( = Sphacelia segetum) produced on the 
grain before the sclerotium is formed, conidiophores short, cyUn- 
dric, arranged in a compact palisade, bearing small, oval, hyaline, 
1-celled conidia. Hosts, rye, wheat, oats and numerous other 
grasses. 

Infection of the ovary at blooming time is followed by complete 
possession and consumption of the ovarial tissue by the mycelium, 
and by considerable development of stroma beyond the ovary. 
On the external much-folded part of this stroma, particularly at 
its distal end, are borne layers of conidiophores and numerous 
conidia and a sweet fluid is exuded. The conidia, carried by in- 
sects, spread summer infection. Later the stroma, losing a large 
part of the distal region, rounds off to a definite sclerotium, smooth, 
firm, blue to black in color, and several times larger than the 
normal grain of the host plant. 

After a period of rest, usually lasting till the following season, 
the sclerotium gives rise to several stalked, capitate, perithecial 
stromata. The perithecia are arranged around peripherally, the 
ostioles protruding and giving the head a rough appearance. The 
sclerotium constitutes the ergot of pharmacy and contains a 
powerful alkaloid capable of causing animal disease if eaten. 

This species appears to be differentiated into a number of 
biologic races. ^^^ 

C. microcephala (Wal.) Tul. infects numerous grasses both in 
Europe and America, being especially destructive to blue grass. 

Two species C. paspali S. & H. and C. rolfsii S. & H. have been 
reported on Paspalum.^^^ 



Ustilaginoidea Brefeld (p. 199) 



150 



Sclerotium formed in the grain of the host, resembling super- 
ficially a smut sorus, in the center composed of closely interwoven 
hyphse, externally the hyphse are parallel, radiating towards the 
periphery and bearing echinulate, globose, greenish conidia; stroma 
with a long sterile stem and a fertile head; perithecia immersed 
in the stroma as in Claviceps; asci and spores also as in Claviceps. 

Two species are known, one on Setaria which produces an 
ascigerous stage, the other on rice, the ascigerous stage of which 




214 THE FUNGI WHICH CAUSE PLANT DISEASE 

is not known but which is placed in this genus on account of the 
similarity of its conidial stage with that of the other species. 

U. virens (Cke.) Tak. Ascigerous stage unknown, sclerotia spher- 
ical, about 5 mm. in diameter; conidia spherical, at first smooth- 
walled, hyaline, at maturity 
echinulate and olive green, 
4-6 IX. 

The short thick walled 
hyphae of the interior of the 
sclerotium are closely in- 
!:> 1 ro T7 ■ "^ • X 1 • terwoven to a false tissue, 

i^iG. 153. — U. virens; a, spores germinated in . ' 

water; h, germinated in bouillon. After toward the periphery they 

become parallel and are di- 
rected radially. Here a yellow layer is produced and spores are 
formed laterally on the hyphae. When mature the spores are in 
mass dark olive-green and form an outer green layer on the 
sclerotium. The spores germinate in water, producing a vegeta- 
tive mycelium which bears secondary spores and somewhat re- 
sembles the mycelium of the Ustilaginales.^^^ Successful inocula- 
tions have not been made. 



Ustilaginoidella Essed (p. 199) 

This is a genus erected by Essed ^"^ to receive the species 
U. musaeperda, which he regards as the cause of the "Panama 
disease" of bananas, at least as it occurs in Suriname. 

Sclerotia similar to those of Ustilaginoidea are found; chlamyd- 
ospores and conidia obtain, among the latter are some of marked 
Fusarium type; others are in pycnidia. 

U. cedipigera Essed is also described by Essed ^^^ as the cause 
of another less important banana disease in Suriname and Colum- 
bia; a disease accompanied by hypertrophy of the base of the 
stem and leading to the common name "bigie footce." This 
fungus differs from the last in its 1 to 2 to 3-celled conidia. 

U. graminicola Essed causes a rice disease. ^"^ This species 
differs but slightly from the two preceding. Chlamydospores 
smaller, conidia 1 to 5-celled. 



THE FUNGI WHICH CAUSE PLANT DISEASE 215 



Loculistroma Patterson & Charles ^^- (p. 199) 

Stromata upright, sessile, at the nodes of the host, fleshy, soft, 
green or black, containing conidial chambers in which are pro- 
duced hyaline filiform conidia and on the outer surface of which 
are borne Cladosporium-like conidia; perithecia scattered, partly 
immersed, ostiolate; asci clavate, cylindric, 8-spored; spores fusi- 
form, 3 to many-septate, olivaceous, biseptate; paraphyses none. 
There is only one species known. 

L. bambusa. P. & C.^^^ 

Stromata 1 cm. long by 2 mm. in diameter; perithecia almost 
spherical, 125 x 100 n; asci 45-50 x 9-10 /x; spores 22 x 4. 5-5 n; 
primary conidia 14-16 x 0.75-1 n; borne in chambers on basidia, 
8 X 0.5 n; secondary conidia external, 1 to 3-celled, borne on 
external olivaceous hyphae. 

It causes a witches' broom of bamboo (Phyllostachys sp.), in 
China. Infection probably occurs in the terminal node. The 
fully developed sclerotia-like structures, resembling those of 
Claviceps, are dark green to black when mature, and consist of 
a central hyaline sclerotial tissue in which are many round 
conidial chambers. Perithecia develop from the peripheral 
layer. 

Dothidiales (p. 124) 

There is only one family the Dothidiaceae. 

Mycelium developed in the substratum, septate, at length form- 
ing a thick, dense, very dark stroma in which the perithecia are 
sunken and with which their walls are completely fused, rarely 
partly free; asci borne from the base of the perithecium; paraphyses 
present or none. 

The Dothidiaceae contain some four hundred species and more 
than twenty-four genera. They differ from the last order in their 
firm black sclerotium-like stromata which are usually pale to white 
within. The perithecia are usually grouped together in great num- 
bers in the external layer of the stroma, sunken in its undiffer- 
entiated body. Conidia of various forms are present. 



216 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Key to Genera of Dothidiaceae 



Stromata at first sunken later more or less 
free 
Perithecia standing free on the stroma ; 

spores at maturity, 4-celled, dark 1. Montagnella., 
Perithecia almost completely embedded 
in the stroma 
Stromata variable, more or less irreg- 
ular in outline but never elongate 
Spores 1-celled 
Spores hyaline 
Asci typically borne at the 
base of the perithecium 
Asci 8-spored 
Spores ellipsoid 

Perithecia few 2. Mazzantia. 

Perithecia numerous. . 3. Bagnisiella. 

Spores filiform 4. Ophiodothis. 

Asci many-spored 5. Myriogenospora. 

Asci borne laterally at the 
equator of the perithe- 
cium, spores ellipsoid. . . 6. Diachora, p. 217. 

Spores brown 7. Auerswaldia. 

Spores 2-celled 
Spores hyaline 

Spores ovate 8. Plowrightia, p. 217. 

Spores needle-like 9. Rosenscheldia. 

Spores colored 

Cells of the spore similar. ... 10. Rousscella. 
Cells of the spore dissimilar. . 11. Dothidea, p. 220. 
Spores several-celled 

Spores with cross walls only 

Spores hyaline, 4-celled 12. Darwiniella. 

Spores colored, multicellular 13. Homostegia. 
Spores muriform 

Spores hyaline 14. Curreyella. 

Spores colored 15. Curreya. 

Stromata elongate, linear or lanceo- 
late 



THE FUNGI WHICH CAUSE PLANT DISEASE 



217 



Spores hyaline 

Spores 1-celled 16. Scirrhiella. 

Spores 2-celled 17. Scirrhia. 

Spores 4 to 8-celled, fusiform. .. 18. Monographus. 
Spores colored, multicellular, fusi- 
form 19. Rhopographus. 

Stromata sunken, permanently united to 
the epidermis and substratum 

Spores 1-celled 20. Phyllachora, p. 220. 

Spores 2-celled 

Spores of similar cells 21. Dothidella, p. 221, 

Spores of dissimilar cells 22. Munkiella. 

Stromata from the first superficial 

Stromata encrusted, widely spreading ... 23. Hyalodothis. 
Stromata cushion-shaped, limited 24. Schweinitziella. 

Of these genera only five are of interest as plant pathogens. 
The majority contain only saprophytes. 



Diachora Miiller (p. 216) 

The genus is easily recognized by its peculiarity of bearing asci 
only as an equatorial band instead of 
on the floor of the perithecia, a char- 
acter unique among the Pyrenomy- 
cetes. 

D. onobrychidis (D. C.) Miill. is 
reported as causing black spots on 
leaves of sainfoin and Lathyrus in 
Europe. 








Plowrightia Saccardo (p. 216) 
Stromata formed within the tissues pio. 154.-d' onobrychidis. E, co- 

of the host plant, erumpent, tuber- nidial stage ;f',ascocarp and asci. 
, 111 After Muller. 

cular or cushion-shaped, depressed or 

elevated, smooth, later frequently wrinkled, white within; asci 
cyhndric, 8-spored; spores ovate, 2-celled, hyaline or light green; 
conidial forms Cladosporium, Dematium, etc. 



218 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Some twenty species are known. They are distinguished from 
Dothidia by the hyaline spores. 







' -si 




T!?^T« 




Ik. l.")") — V nioil)<)sa h, maKiiihcd section of a knot showing the 
poiithcda, c, conidiophon ^ .uid conidia; d, section of a peri- 
thecium showing numeioub abci, one of which is shown more highly 
magnified at e; /, several of the two-celled ascospores germinating 
in water. After Longyear. 

P. morbosa (Schw.) Sacc^^^^-^"' -^^ 

Stromata elongate, cushion-shaped, rarely tubercular, up to 2 or 




THE FUNGI WHICH CAUSE PLANT DISEASE 219 

3 dm. long; perithecia scattered, often entirely suppressed; asci 
about 120 n long; spores variously arranged in the ascus, 16-20 x 
8-10 IX, ovate, the cells usually unequal; paraphyses filiform. 

Conidia ( = Cladosporium sp.) pro- 
duced upon greenish areas on the young 
stromata; conidiophores erect, flexuose, 
septate, simple, 40-60 x 4-5 /x; conidia 
borne singly at the apex of the conidio- 
phore, obovate, unicellular, light brown, 
about 6-8 X 2-5 /z. 

Hosts: Cultivated sour cherry and 
plum, wild red and yellow plum, 
Chickasaw plum, choke cherry, wild 
red cherry and wild black cherry, fig. 156.— p. morbosa; host 

Fnimrl nnlv in Amprinn showing o p port u ni ty for 

i^OUna Omy m America. lodgement for spores in a 

The mycelium invades the cambium crotch. After Lodeman. 
of twigs and from it grows outward into the bark region causing 
the bark elements to overgrow and the twig to swell slightly dur- 
ing the first summer. With the renewed growth of the following 
spring the swelling proceeds rapidly. During May to June the 
mycelium ruptures the bark which is soon lost and a dense fun- 
gous pseudoparenchyma is formed. From this the conidiophores 
appear, forming a velvety growth of olivaceous color. At this 
period the knot consists largely of a fungous stroma with an ad- 
mixture of bark elements and even some wood cells. 

Later in the season conidiophores cease to form and the knot 
turns to a black hard stroma. Perithecia now become easily 
visible in this black stroma and in January or later the asci mature. 
Farlow has described " stylospores " (a form named Hendersonula 
morbosa by Saccardo the connection of which to P. morbosa is 
in some doubt) and spermogonia and pycnidia. Humphrey ^^^ 
from ascospores, in artificial media, raised a pycnidial form which 
seemed to be distinct from any of these. That the fungus is 
the actual cause of the black knot was first demonstrated by 
Farlow ^^^ in 1876, though the fungus was described as early as 
1821 by Schweintiz.158 

Lodeman ^^^ considered that infection is favored by cracks 
existing at crotches of the tree. Fig. 156. 



220 



THE FUNGI WHICH CAUSE PLANT DISEASE 



P. ribesia (Pers.) Sacc. is found in Ribes twigs and 

P. virgultorum (Fr.) Sacc. on birch. Both are European. 

P. agaves occurs on the maguey. ^^^ 

Dothidea Fries, distinguished from Plowrightia by its colored 
spores, contains some twenty-five species which occur on twigs of 
Sambucus, Rosa, Buxus, Betula, Juniperus, Quercus and many 
other woody plants. 

D. rosae Fries, is common as the supposed cause of a rose tumor. 

D. noxia Ruhl. causes an oak twig disease in Germany. ^^^ 



Phyllachora Nitschke (p. 217) 

Stroma sunken, united to the parenchyma and epidermis of 
the host leaf, rarely erumpent, encrusted, usually jet-black; peri- 
thecia sunken in the stroma, rather numerous, 
with more or less distinct ostioles; asci cyhndric, 
8-spored; spores ellipsoid or ovate, 1 -celled, 
hyaline or yellowish; paraphyses present. 

More than two hundred species, largely 
tropical, are known on a wide range of hosts. 
All are leaf parasites. 

P. graminis (Pers.) Fcl. Stromata variable in 
size and form, causing conspicuous black spots 
on leaves of the host; perithecia immersed, os- 
tiolate; asci short-pedicillate, cylindric, 70-80 x 
7-8 n; spores obliquely uniseriate, ovoid, hya- 
line, 8-12 X 4-5 n; paraphyses filiform. No 
conidia are known. 

This fungus occurs on many grasses and 
After sedges with slight injury to them. 

P. pomigena (Schw.) Sacc. produces black 
spots, scarcely ever above 5 mm. in diameter, on apples, especially 
the Newton Pippin, in the eastern United States. Little is 
known of the species. 

P. trifolii (Pers.) Fcl. causes small black spots 1 mm. or less 
in diameter on clover leaves; asci cylindric; spores uniseriate, oval, 
hyaline, 8-10 x 5-6 fx. 

Conidia ( = Polythrincium trifolii) precede the asci on the stro- 




FiG. 157. — P. gram- 
inis. B, stroma in 
section ; C, an ascus 
and spores 
Winter. 




THE FUNGI WHICH CAUSE PLANT DISEASE 221 

mata; conidiophores wavy or zigzag, erect, simple, black, conidia 
obovate, 1-septate, constricted, pale olivaceous, 20-24 x 9-10 n. 

The conidial form is very common on various species of clover 
in Europe and America while the ascosporic stage is mentioned 
only by Cooke '*'° and Clevenger.^^^ 

P. cynodontis (Sacc.) Niess. on Cynodon, P. poae (Fcl.) Sacc. 
on Poa and P. dapazioides (Desm.) Nke. on 
Box and Rhododendron are European. 

P. makrospora Zimm. occurs on Durio zibel- 
linus; 

P. sorghi V. Hoh. on Sorghum vulgare.^^" 

Dothidella Spegazzini differs from Phyllachora 
in having 2-celled hyaline spores, the cells un- 

, . . ^, ^f., . » Fig. 15S. — D. betu- 

equal m size. Ihere are over mty species of Una. Asci and 
the genus. Epiphyllous, subrotund confluent, winter.^' ^^^^^ 
convex, grayish-black, on white spots; ostiole 
granular; asci cylindric, short-stipitate, 60-70 x 8 m; spores ob- 
long, ovate oblong, hyaline, 10-15 x 5 m- D. ulmi Duv.^^'^ Co- 
nidia =Septoria ulmi and Piggatia astroidea. On elm in Europe 
and America. Other species are D. thoracella (Rostr.) Sacc. on 
Sedum, in Europe, D. betulina (Fries) Sacc. on Betula in Europe 
and Asia. 

Sphaeriales (p. 124) 

Mycelium chiefly confined to the substratum; perithecia vari- 
able, usually globose, with a more or less elongated ostiole, hairy 
or smooth, free on the substratum, more or less deeply sunken, or 
borne on or sunken in a stroma; asci borne basally, variable in 
size, opening by a pore; spores variable, globose, ovate to elongate 
or filiform, hyaline or colored; paraphyses usually present; conidial 
forms various. 

The stromata may vary from a delicate hyphal weft to a firm 
crustaceous structure. The pycnidia are mostly carbonous, black 
and brittle. Conidia of many forms are present and often con- 
stitute the only truly parasitic form of the fungus; the asci- 
gerous form developing only after the death of the part of the 
host involved. 



222 



THE FUNGI WHICH CAUSE PLANT DISEASE 



The order is very large, embracing according to Engler & Prantl 
some eighteen families and over six thousand species. 



Key to Families of Sphaeriales 

Perithecia free, either without a stroma, 
partly seated in a loose mass of myce- 
lium, or sessile above an imperfect 
stroma 
Walls of the perithecia thin and mem- 
branous; asci soon disappearing 
Perithecia always superficial, with 
copious tufts of hair at the mouth 
Perithecia usually sunken, with only 

short hairs about the mouth 

Walls of the perithecia coriaceous or car- 
bonous 
Perithecia either entirely free, or with 
the base slightly sunken in the 
substratum or stromatic layer 
Stroma wanting or only thread-like 
or tomentose 
Mouths of the perithecia mostly in 
the form of short papillae. . . . 
Mouths of the perithecia more or 
less elongate, often hair-like. . 
Stroma present 

Stromata mostly well developed, 
indefinite; perithecia in close 
irregular masses, never flask- 
like of funnel-like at the apex 
Stromata small, sharp-bordered; 
perithecia in rows or in regu- 
lar rounded masses, flask- 
shaped with funnel-shaped 

mouths 

Perithecia more or less deeply sunken 

in the substratum at base, free 

above 

Mouths of the perithecia circular in 

outline 



1. Chaetomiaceae. 

2. Sordariacese, p. 224. 



3. Sphaeriaceae, p. 225. 

4. Ceratostomataceae, 
p. 232. 



5. Cucurbitariaceae, p. 234. 



6. Coryneliaceae. 



7. Amphisphaeriaceae. 



THE FUNGI WHICH CAUSE PLANT DISEASE 223 

Mouths of the perithecia laterally 

compressed 8. Lophiostomataceae. 

Perithecia without a stroma, and sunken in 
the substratum, or with a stroma 
Stromata none; perithecia rarely united 

above by a black tissue (clypeus) , 

Asci not thickened at the apex, mostly 
projecting at maturity 
Walls of the perithecium thin, cori- 
aceous; mouth mostly short or 
plane 
Asci clinging together in fascicles, [p. 235. 

without parapliyses 9. Mycosphaerellaceae, 

Asci not fasciculate; with para- 

physes 10. Pleosporaceae, p. 250. 

Walls of the perithecia carbonous or 
thick coriaceous; spores large, 

mostly enveloped by gelatine. . 11. Massariaceae, p. 262. 
Asci usually thickened apically, open- 
ing by a pore; perithecia usually 
beaked 

Perithecia without a clypeus 12. Gnomoniaceae, p. 263. 

Perithecia with a clypeus 13. Clypeosphaeriaceae, 

Perithecia firmly imbedded in a stroma, p. 276. 

the mouths only projecting, or becom- 
ing free by the breaking away of the 
outer stromatic layers 
Stromata fused with the substratum 

Conidia produced in pycnidia 14. Valsaceae, p. 277. 

Conidia developed from a flattened 

surface 15. Melanconidaceae, 

' Stromata formed almost wholly of hard- p. 279. 
ened fungal Ityphse 
Spores small, cylindric, 1-celled, 
mostly curved, hyaline or yel- 
lowish-brown 16. Diatrypaceae, p. 281. 

Spores rather large, 1 to many-celled, 
hyahne or brown, conidia mostly 

in cavities jn the stroma 17. Melogrammataceae, 

Spores 1-celled, rarely 2-celled, p. 282. 

blackish-brown. Conidia devel- 



224 THE FUNGI WHICH CAUSE PLANT DISEASE 

oped on the upper surface of 

the young stroma 18. Xylariaceae, p. 284. 

Families Nos. 1, 6, 7, 8, 17 are saprophytes on plants and 
animals. 

Sordariaceae (p. 222) 

Perithecia superficial or deeply sunken in the substratum, often 
erumpent at maturity, thin and membranous to coriaceous, slightly 
transparent to black and opaque; stroma usually absent, if present 
the perithecia immersed in it with projecting papilliform beaks; 
asci usually very delicate, cylindric, 8-spored; spores usually 
dark-colored; paraphyses abundant. 

A small order, chiefly dung inhabiting. 

Key to Genera of Sordariaceae 
Spores continuous 
Without a stroma 

Neck of the perithecium hairy 1. Sordaria. 

Neck of the perithecium with black 

spines 2. Acanthorh3rnchus, p. 224. 

With a stroma 3. Hypocopra. 

Spores 2 or more celled 
Spores 2-celled 

Spores hyaline 4. Bovilla. 

Spores dark-brown 5. Delitschia. 

Spores 4 to many-celled 

Stroma absent 6. Sporormia. 

Stroma present 7. Sporormiella. 

Spores muriform; stroma present 8. Pleophragmia. 

Acanthorhynchus Shear ^^^ 

Perithecia scattered, submembranous, buried, beaked, the beak 
with non-septate spines; asci opening by an apical pore; paraphyses 
present, septate; spores continuous, brownish-yellow. 

There is a single species, A. vaccinii Sh.^^^ 

Amphigenous: perithecia subglobose to flask-shaped, scarcely 
erumpent, 120-200 jj. in diameter, neck stout, exserted, ^U-^U the 
length of the perithecium; spines 50-70 x 8-9 m; asci subelliptic 
to somewhat clavate, subsessile, 120-155 x 24-44 /x; spores oblong- 



THE FUNGI WHICH CAUSE PLANT DISEASE 



225 



elliptic, surrounded by a mucilaginous layer, 24-32 x 12-18 n; 
paraphyses exceeding the asci. 

The mycelium produces rot of cranberries, also leaf spots, but 
the fructification of the fungus is rarely found in nature except on 





Fig. 159. — A single perithecium 
of A. vaccinii taken from a 
pure culture on corn meal. 
After Shear. 



Fig. 160. — Acan- 
thorhynchus; a 
germinating as- 
cospore bearing 
the peculiar 
appressorium, 
17, view from 
above. After 
Shear. 



old fallen leaves. In culture, however, it produces abundant peri- 
thecia. When on the leaf the perithecia are subepidermal and 
are sparsely scattered over the lower surface. No conidial or 
pycnidial form is known. Remarkable appressoria are produced 
by the germ tubes from the spores, Fig. 160. 

Sphaeriaceae (p. 222) 

Perithecia single or clustered, free or with a false stroma in 
which they are more or less sunken; walls leathery, horny or woody; 
ostiole rarely elongate, usually papillate; spores frequently ap- 
pendaged. 

The family is distinguished by its free perithecia with papillate 
ostioles. It contains about seven hundred species. 

Key to Genera of Sphaeriacese 

Perithecia hairy above, rarely smooth above 
and hairy beneath 
Spores 1 or 2-celled 

Perithecia thin, cuticulate or leathery 
Spores 1-celled; asci apically thick- 
ened 1. Niesslia. 



226 THE FUNGI WHICH CAUSE PLANT DISEASE 

Spores 2-celled; asci not apically 

thickened 2. Coleroa, p. 227. 

Perithecia thick, leathery or carbon- 
ous 
Spores hyaline, sometimes becoming 
brown, 1 or 2-celled 

Spores ellipsoid 3. Trichosphaeria, p. 228. 

Spores cylindric, bent 4. Leptospora. 

Spores dark colored, 2-celled 5. Neopeckia. 

Spores more than 2-ccllcd 

Perithecia thin, leathery or cuticula- 

rized 6. Acanthostigma, p. 229. 

Perithecia thick, carbonous or woody 
Spores 4-celled, the two middle cells 

brown, the end cells hyahne. .. . 7. Chaetosphaeria. 
Spores many-celled, concolorous, 
hyaline or brown 

Spores spindle-form 8. Herpotrichia, p. 229. 

Spores elongate-cylindric 9. Lasiosphaeria. 

Perithecia smooth 

Perithecia tuberculate or irregularly 
thickened 
Spores ellipsoid, 2 to many-celled, 

hyaline 10. Bertia. 

Spores spindle-form, 4 to 11-celled, 

hyaline 11. Stuartella. 

Spores muriform, dark 12. Crotonocarpia. 

Perithecia not tuberculate 
Spores 1-celled, dark 
Spores with hyaline appendages on 
each end ; perithecia thick, leath- 
ery 13. Bombardia. 

Spores unappendaged, perithecia 

carbonous 14. Rosellinia, p. 230. 

Spores 2 to many-celled 

Perithecia thin, leathery; spores 2- 

celled 15. Lizonia. 

Perithecia thick, leathery or car- 
bonous, brittle 
Spores ellipsoid 
Spores 2-celled 



THE FUNGI WHICH CAUSE PLANT DISEASE 227 

Spores hyaline, sometimes be- 
coming brown 16. Melanopsamma. 

Spores hyaline to green 17. Thaxteria. 

Spores dark-colored 18. Sorothelia. 

Spores 3 to many-celled 

Spores hyaline 19. Zignoella. 

Spores dark-colored 20. Melanomma. 

Spores elongate, spindle-form, hya- 
line, many-celled 21. Bombardiastrum. 

Coleroa Fries (p. 226) 
Perithecia free, small, globose, flask-shaped; asci 8-spored; spores 

V:' •:■:'--■■ ■ '-^^^^ 




Fig. 161. — C. chsetomium. C, perithecia; D, asci. 
After Lindau and Winter. 



ovate, 2-celled, hyaline, green or golden-brown; paraphyses poorly 
developed. 

Conidia= Exosporium. 

This genus, of some thirteen species all of which are parasitic, 
is quite similar to Venturia. The chief economic species are C. 
chaetomium (Kze.) Rab. (Conidia= Exosporium rubinus) on Rubus 
in Europe and C. sacchari v. B. d H., on sugar cane in Java.^^^ 



228 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Trichosphaeria Fuckel (p. 226) 

Perithecia usually free, globose, woody or carbonous, hairy, 
ostiole flat or papillate; asci-cylindric,8-spored; spores 1 to 2-celled, 
hyaline; paraphyses present. 

There are some forty species, mainly saprophytes. 

T. sacchari Mass.^^^' ^^^ 

Perithecia broadly ovate, dark-brown, beset with brown hairs; 
spores elongate-ellipsoid, 1-celled; the conidial forms are various 




.%f4Ae^ A 



■p i 

Fig. 162.^Trichosph:Bria. E, habit sketch; G, conidial 
stage. After Lindau, Winter and Brefeld. 




and their genetic connection is by no means certain. (1) (=Conio- 
thyrium megalospora) Pycnidia 1-3, on a dark-colored, parenchy- 
matous stroma; conidia elongate, straight or curved, brownish, 
12 X 5 /x, (2) The macroconidia ( = Thielaviopsis ethaceticus) 
see p. 596, are often found forming intensely black, velvety 
layers lining cracks and cavities in diseased canes. (3) Micro- 
conidia produced on the surface in Oidium-like chains. Their 
connection with this fungus is disputed and uncertain.^^^ 
It is a sugar cane parasite. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



229 



Acanthostigma de Notaris (p. 226) 

Perithecia free, globose or ovate, very small; walls leathery, 
black, beset with stiff bristles, ostiole 
short; asci usually cylindric, rarely 
ovate, 8-spored; spores spindle-shaped, 
multicellular by cross walls, hyaline; 
paraphyses few or none. 

There are some thirty species, 
mostly saprophytes. 

A. parasiticum (Hart.) Sacc.^^""^^^ 

Perithecia globose, minute, with 
rigid divergent hairs, 0.1-0.25 mm. 
in diameter; asci 50 fj. long, early 
disappearing; spores fusoid, straight 
or curved, smoky, 15-20 /x, continuous 
or 2 to 3-septate. 

Common on leaves of Abies, Tsuga 
and other conifers in Europe and 
America. The hyaline mycelium 
grows on the lower sides of branches 
and onto the leaves killing them 
and matting them to the branches. 
The mycelial cushions later turn brownish and eventually very 
small perithecia form on them. 




Fig. 163.— Peiithecium of A. Tri- 
chosphaeria parasiticum, show- 
ing ostiole, bristles, asci, para- 
physes and spores. After 
Hartig. 



Herpotrichia Fuckel (p. 226) 

Perithecia superficial, globose or subglobose, texture firm, 
coriaceous to subcarbonous, hairy or smooth, ostiole papillate 
or not; asci oblong to clavate; spores fusiform, 2 or many-celled, 
hyaline or brown; paraphyses none. 

The species, numbering about twenty-five and growing on 
woody plants, are mostly saprophytes. 

H. nigra Hart.^^^ 

Mycelium dark-brown, widely spreading, haustoria slender, 
Hghter in color; perithecia globose, dark, 0.3 mm. in diameter; 
asci elongate, 76-100 x 12 /x; spores constricted, 1-3 septate. 




230 THE FUNGI WHICH CAUSE PLANT DISEASE 

Common in Europe on branches of Larix, Abies, Juniperus, 
spruce and pine, doing great damage. The dark-brown mycelium 
grows over the plant, killing and matting the leaves. 

Rosellinia Cesati & de Notaris (p. 226) 

Perithecia superficial, but often with the bases more or less 
sunken in the substratum, coriaceous or car- 
bonous; brittle, spherical or ovate, bristly or 
not; asci cylindric, 8-spored; spores elhptic, 
oblong or fusiform, 1-celled, brown or black; 
paraphyses fusiform. Conidia of the type of 
Coremium, Sporotrichum, etc. 

In most cases the active parasitic stage 
occurs on roots and consists of a vigorous 
white mycelium, which remains for a long time 
Fig. 164. — Herpotri- sterile, developing large branching and inter- 

chia. B, ascus; . , /t-T \ i • i i 

c, spore. After lacmg rhizomorphs (Dematophora) which later 
^° ^^' become brown. These resemble somewhat, but 

are distinguishable from, the rhizomorphs of Armillaria mellea; 
again, they are Rhizoctonia-like. 

There are over one hundred seventy species, mostly saprophytic. 

R. necatrix (Hart.) Berl.i^"- ^^^ 

A destructive fungus, long known as Dematophora necatrix, 
possesses a white mycelium which invades the small roots, thence 
passes to larger ones, extending in trees through the cambium 
and wood to the trunk, occasionally rupturing the bark and pro- 
ducing white floccose tufts. Sclerotia of one or more kinds are 
produced in the bark and often give rise to conidia on tufted conidi- 
ophores in a Coremium-like layer (Fig. 165). The mycelium, 
when old, turns brown and produces large branching, interlacing 
rhizomophic strands which spread to the soil, or wind about the 
roots. 

In some instances the connection of the ascigerous with the 
sterile or conidial stages is well established; in others the asci 
have been found but rarely and the evidence of genetic connection 
is not complete. It is probable that some fungi reported as Dema- 
tophora do not in reality belong to Rosellinia. 

The fungus attacks nearly all kinds of plants. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



231 



Perithecia were found by Viala ^^^ and by Prillieux ^^^ on old 
wood, long dead from such attack. These belong to the genus 
Rosellinia and are believed to present the ascigerous form of Dema- 
tophora necatrix. Similar claims of relationship of this fungus to 
several other genera have 
been made and its actual 
position cannot be consid- 
ered as established with 
certainty. 

R. massinkii Sacc. 

Perithecia sparse, globose 
or depressed, carbonous, 
165 ix) asci cylindric, 54 x 
8 )u; spores dark-brown, el- 
Uptic, 1-rowed, 10 x 5 /x. 

It is reported by Halsted 
on hyacinth bulbs. 

R. bothrina B. & Br. is 
the cause of a tea root 
disease. 

Pseudodematophora 
closely allied to the above 
forms is described by Beh- 
rens ^"^^ on diseased grape 
roots. 

R. quercina Hart, is 
parasitic on roots and stems 
of young oaks, producing a 
Rhizoctonia-like mycelium, at first white, later brown. Perithecia 
are usually abundant. Black sclerotia the size of a pin head are 
also present superficially. 

R. radiciperda Mas. closely allied to R. necatrix, affects a large 
number of hosts, among them apple, pear, peach, cabbage, and 
potato. 

An undetermined species of this genus is said to cause a cran- 
berry disease.^^^ Shear, however, in his extensive studies of cran- 
berry diseases, did not find it. 

R. aquila (Fr.) d. Not. injures Morus. Its conidial form is 




Fig. 165. — R. necatrix. 4< coremium and co- 
nidia; 5, perithecia extruding spores; 6, asci 
and paraphyses. After Hartig, Prillieux and 
Viala. 



232 THE FUNGI WHICH CAUSE PLANT DISEASE 

Sporotrichum fuscum. R. ligniaria (Grev.) Nke. occurs on ash 
trees. R. echinata Mas. is reported on "all kinds of Dicotyledon- 
ous shrubs and herbs." 

Melonomma Fcl. in the species M. henriquesianum Bros. & 
Roum. is parasitic on cacao stems. 

M. glumarum Miy. is on rice.^°^ 

Ceratostomataceae (p. 222) 

The fungi of this family are very similar to the Sphaeriacese, 
but are distinguished by less pronouncedly carbonous perithe- 
cia which may be merely membranous, and open by an elongate, 
beak-like ostiole. It is a family of only about one hundred 
twenty-five species, chiefly saprophytes. 

Key to Genera of Ceratostomataceae 

Spores 1-celled 

Spores hyaline 1. Ceratostomella, p. 232. 

Spores brown 2. Ceratostoma. 

Spores 2-celled 

Spores hyaline 3. Lentomita. 

Spores dark-colored 

Perithecia on a cottony stroma 4. Rhynchomeliola. 

Perithecia not on a cottony stroma. . . 5. Rhynchostoma. 
Spores many-celled 

Spores with cross walls only 

Spores elongate, 4 to many-celled, hya- 
line or brown 6. Ceratosphaeria. 

Spores filiform, many-celled, usually 
hyaline 

Perithecia erect, astromatic 7. Ophioceras. 

Perithecia horizontal in stromatic 

nodules 8. Cyanospora, p. 233. 

Spores muriform 9. Rhamphoria. 

Ceratostomella Saccardo 

Perithecia superficial, firm; asci ovate, 8-spored, disappearing 
early; spores elongate, blunt or pointed, 1-celled, hyaline. About 
thirty species. An extensive study of the genus was made by 



THE FUNGI WHICH CAUSE PLANT DISEASE 



233 



Hedgcock ^'^ who recognizes several species as discoloring lumber. 
C. pilifera (Fr.) Wint. has been described in detail by von 
Schrenk as the cause of a blue color in pine wood/^^ 

Cyanospora Heald & Wolf (p. 232) 

Perithecia solitary or in clusters of two or three on stromatic 
nodules, immersed, horizontal; ostiole lateral, neck short; asci 






Fig. 166. — C. pilifera peri- Fig. 167. — C. albicedrse. Sec- 
thecium, asci and tion of a perithecium in 



spores. 
Schrenk. 



After von 



its stroma. 
Wolf. 



After Heald and 



Fig. 168.— C. albicedrje. 
Upper part of an ascus 
showing thickened 
apical wall and coiled 
spores. After Heald 
and Wolf. 



slender, linear, surrounded by a gelatinous matrix, apically thick- 
ened; spores filiform, multiseptate, hyaline. 

A single species. 

C. albicedrae Heald & Wolf. 

Stroma on bark or wood of the host, varying from gray on the 
bark to black on wood, lenticular, 1-2 mm. long, solitary or clus- 
tered; perithecia 825-1200 x 260-400 n; asci 700-1100 x 8-10 /i; 
spores 600-1000 x 3 /z; paraphyses numerous, continuous, 1 fx 
in diameter. 

The fungus is described in detail by Heald and Wolf ^^^ as caus- 



234 THE FUNGI WHICH CAUSE PLANT DISEASE 

ing whitening of the mountain cedar (Sabina sabinoides) from 
Texas to Central Mexico. The seat of infection is the younger 
twigs and the young trees, especially where in shade. The disease 
may kill the entire trees. 

Cucurbitariaceae (p. 222) 

Perithecia clustered, immersed at first, then erumpent, seated 
on a stroma, leathery to carbonous; paraphyses present. The 
species numbering about one hundred fifty are mostly saprophytes. 

Key to Genera of Cucurbitariaceae 
Spores 1-celled 
Asci 8-spored 

Spores large, green 1. Bizzozeria. 

Spores small, hyaline 2. Nitschkia. 

Asci many-spored. 3. Fracchiaea. 

Spores 2 or more-celled 
Spores 2-celled 

Perithecia bristly, spore walls hyaline . . 4. Gibbera, p. 234. 

Perithecia smooth, spore walls brown. . 5. Otthia. 

Spores more than 2-celled 6. Gibberidea. 

Spores muriform 7. Cucurbitaria, p. 234. 



Gibbera Fries 



179 



Perithecia cespitose on a superficial, thick, Demataceous, conidia- 
bearing, carbonous, fragile, bristly stroma; ostiole papillate; asci 
cylindric, 8-spored; spores oblong, elliptic, hyaline, uniseriate. 

The genus contains some half dozen species, one of which G. 
vaccinii (Sow.) Fr. occurs on Vaccinium in Europe. The conidial 
form is Helminthosporium vaccinii. Fig. 169. 

Cucurbitaria Gray 

Perithecia cespitose or more rarely gregarious on a crustaceous 
stroma covered by Demataceous hyphse, spherical, glabrous, black, 
coriaceous; asci cylindric, 8-spored; spores uniseriate, oblong or 
elliptic, muriform, brownish, paraphyses present. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



235 



Over seventy species, several of which are parasitic but none of 
importance in America. 

C. laburni Pers. is on branches of Cytisus; 

C. sorbi Karst on Sorbus twigs; 

C. pityophila (Kze.) d Not. on various conifer twigs; 

C. berberidis (Pers.) Gray on Berberis; 

C. elongata (Fr.) Grev. on Robinia; 

C. piceae Brothwick, on Picea. 

Mycosphaerellaceae (p. 223) 

Perithecia mostly subepidermal, rarely subcuticular, finally 
more or less erumpent or even superficial, membranous or leathery, 



Fig. 169.— 
Gibbera vac- 
cinii. An 
ascus. After 
Winter. 




Fig. 170. — Cucurbitaria berberidis. Q, 
habit sketch ; H, ascus. After Lindau 
and Winter. 



fragile; asci fasciculate, 8-spored; spores variable, septate, rarely 
muriform, hyahne to dark-brown; paraphyses none. 

This family of over seven hundred species contains many sap- 
rophytes and several very important parasites. 



Key to Genera of Mycosphaerellaceae 

Spores 1 to 2-celled 
Spores hyaline or green 

Spores 1-celled or not clearly 2-celled 

Perithecia very small, on a basal 

growth of thick branched hyphse 



1. Ascospora, p. 236. 



236 THE FUNGI WHICH CAUSE PLANT DISEASE 

Perithecia without such a basal 
growth 

Spores typically 1-celled 2. Massalongiella. 

Spores usually unequally 2-celled. 3. Guignardia, p. 237. 
Spores 2-celled 

Perithecia produced on living 

plants 4. Stigmatea, p. 243. 

Perithecia appearing after the death 

of the host 5. Mycosphaerella, p. 243. 

Spores dark-colored 

Spores 1-celled 6. Miillerella. 

Spores 2-celled 

Lichen-inhabiting 7. Tichothecium. 

Not Hchen-inhabiting 8. Phaeosphaerella. 

Spores several-celled, hyaline 
Spores elongate, with cross walls only 

Spores 2 to 4-celled; on lichens 9. Pharcidia, p. 250. 

Spores 4-celled; with a cottony subicu- 

lum 10. Sydowia. 

Spores many-celled 11. Sphaerulina, p. 250. 

Spores muriform 12. Pleosphaerulina,p.250. 

Ascospora Fries (p. 235) 

Perithecia borne on a subiculum of thick, brown, much-branched 
hyphse, globoid, black, carbonous; asci clavate, 
clustered, 8-spored, small; spores 1-celled, hya- 
line; paraphyses none. 

■^ ^^^l^!^^ About half a dozen species, one of which is 

_, ,_, , said by Vuillemin ^^° to be the ascigerous form 

Fig. 171. — Ascospora '' ... • 

himantia. Asci. of Coryneum beyerinckii, a wound parasite 
common on drupaceous trees causing gum- 
mosis. Cultural evidence of this relationship is lacking, but his 
hypothesis may be tentatively assumed. 

A. beyerinckii Vuil. Perithecia black, depressed-globose, apapil- 
late; ostiole indistinct or absent, 100-130 /x in diameter; spores 
elliptic-fusoid, ends obtuse, continuous, hyaline, guttulate, 15 x 5- 
7 n. 

Conidia, 1. (=Phyllosticta beyerinckii) pycnidia globoid with 
hyaline spores. 




THE FUNGI WHICH CAUSE PLANT DISEASE 237 

Conidia, 2. (=Coryneum beyerinckii) conidiophores short, 
crowded, from a minute subepidermal stroma; conidia single, 
elliptic-oblong, 1 to 5-septate, brown, about 36 x 15 ix. On 
drupaceous hosts. 

In spots on the bark the mycelium is often sterile, but when 
it becomes old distinct pustules usually show in a well developed 
subepidermal stromatic tissue and from these pustules, as they 
rupture the epidermis, the conidiophores are produced. Conidia 
usually abound on the surface of twigs which have borne affected 
leaves. They germinate readily and produce either a sooty super- 




FiQ. 172. — Section through a Coryneum pustule on peach. 
After Smith. 

ficial mold or if on new bark enter the host tissue and induce 
spotting. 

The conidial stage (Coryneum) of the fungus was grown in arti- 
ficial culture by Smith ^^^ but no ascigerous stage corresponding 
with that of Vuillemin was found. 

A. geographicum (D. C.) Desm. is common on leaves of pome 
fruits and A. padi Grev. defoliates cherries in Europe. 

Guignardia Viala & Ravaz (p. 236) 

Perithecia sunken, globoid or flattened, black, leathery; ostiole 
flattened or papillate; asci clavate, 8-spored; spores ellipsoid or 
fusiform, hyaline, somewhat arched, 1 or 2-celled; paraphyses 
none. 



238 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Over one hundred thirty species are known. Some are impor- 
tant parasites. 

Conidial forms are found in Phoma and Phyllosticta. 

G. bidwellii (E.) V. & R."' '''"^^^ 

Perithecia minute, globose, subepidermal, erumpent, perforate; 
asci clavate-cylindric, obtuse, 60-70 x 10-13 /x; spores elliptic to 
oblong, continuous, 12-17 x 43^-5 fi. 

Conidia ( = Phoma uvicola, Phyllosticta labruscse, Naemospora 
ampelicida) borne in pycnidia 180 x 180 fx, subepidermal, elliptic, 



oscospore 

qerminof/oiT 




Fig. 173. — Diagrammatic section of a perithecium con- 
taining ascospores. Germination of a spore at the 
right. After Reddick. 

thick- walled; conidiophores short, simple; conidia ovate to elliptic, 
8-10 X 7-8 ^t. Filiform microconidia ("spermatia") are borne in 
flask-shaped pycnidia 0.1-0.2 x 0.45-0.46 /z. 

The fungus has been placed successively in the genera Sphaeria, 
Physalospora, Laestadia and Guignardia. 

An extensive synonomy is given by E. Rose who concludes 
that the name should be G. ampelicida. 

It is found on all green parts of Vitis and Ampelopsis, the as- 
cigerous stage common only on the mummified fruits. 

Perithecia were first found in 1880 by Dr. Bidwell in New Jersey. 
They are abundant on berries, which have wintered out doors. 

Reddick admirably describes the development of the spots as 
follows: 



THE FUNGI WHICH CAUSE PLANT DISEASE 



239 



On the leaves the first evidence of the spot is the slight blanching 
of a single one of the smaller areola of the leaf. Soon the blanch- 
ing extends to adjacent areolae, and if an areola is entered it is 
usually entirely involved. The small veinlets form the margin 
of the spot so that the outline is finely crenulate. By the time 
the spot is .3 to .4 mm. in diameter it has a cinereous appearance. 
The margin, while sharply defined, is not changed in color. By 
the time the spot is 1 mm. in diameter, the margin appears as a 
black line, while the remainder of the spot is grayish-brown. A 



Germinated 
053i=, Spores 




Fig. 174. Diagrammatic section througii a pycnidium, show- 
ing how the spores are produced and how they germinate. 
After Reddick. 

little later the margin is a brownish band and the brown gradually 
extends inward until the whole spot is covered. As soon as the 
brown band attains some width the blackish line on the margin 
is to be seen again. A second wave of deeper brown may pass 
across the spot but sometimes it does not get entirely across and 
thus leaves a marginal band of a deeper brown than the central 
disc. Spots vary in size from 1 m.m. up to 8 mm. in diameter, but 
in general are 3 to 5 mm. or larger. Occasionally the whole leaf is 
destroyed but this is by the coalescence of many spots. When 
the spot has attained full size pycnidia protrude from under the 
cuticle and either dot the entire surface of the spot with minute 
specks or are more often confined to a more or less concentric ring. 
The different shades of color are apparent on the under side of 



240 



THE FUNGI WHICH CAUSE PLANT DISEASE 




the leaf on such varieties as have leaves which are smooth beneath. 
The pyncidia, however, have never been seen on the under side 
of the leaf in our varieties. 

On stems, tendrils, peduncles, petioles and leaf veins the 
spot in its first appearance is a small darkened depression which 
soon becomes very black. On a cane the lesion rarely extends 
more than a quarter of the way round, while on a tendril or leaf 
petiole it may extend from half to all of the way round. On shoots, 

the lesions never extend so 
deep as to cut off the sap 
supply, but on petioles this 
occasionally happens, rarely 
so on peduncles, and quite 
commonly so on pedicels and 
tendrils. The first indication 
of Black Rot on the berry 
is the appearance at some 
point of a small circular 
blanched spot, scarcely 1 mm. 
in diameter. The blanching 
is so sHght as to be detected 
only by careful observation. It rapidly becomes more apparent 
and has a whitish appearance, the contrast becomes more ap- 
parent by the appearance of a brownish line at the mar- 
gin. The whitish center increases in size and the brownish or 
reddish-brown ring increases in diameter as well as in width 
and is quite evident when the spot is 2 mm. in diameter. When 
the spot is 3 mm. in diameter the ring is one-half mm. in width 
and enough darker to give a bird's eye effect (a light circular 
disc with an encircling darker band). The spot rapidly increases 
in size so that in twelve hours more it may be 6 to 8 mm. in diam- 
eter, and the encircling band nearly 2 mm. in width. After five 
hours more, the spot is 8 or 9 mm. in diameter and there begins 
to appear an outer darker band and an inner lighter brown one 
which have in some cases a much lighter line between them. The 
aureole is thus composed of two or three bands or rings. Eighteen 
hours later, the spot is 1 cm. or more in diameter, is distinctly 
flattened, and numerous minute brown specks appear on the 



Fig. 175. — Section of a pustule showing 
« microconidia. After Longyear. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



241 




white center of the spot. In five hours more they are so numerous 
as to give a blackish appearance. 

In New York, Redchck found that the asci begin to ripen in May 
and continue to mature throughout the summer being still abundant 
in October. The asci swell in water often to twice the length 
given above; spores are forcibly ejected from the 
asci at maturity, being thrown to a height of 
2 to 4 cm. There is at one end of the asco- 
spore a hyaline vesicle which probably aids in 
fixing it to the host.^^^ They germinate but 
slowly, requiring from thirty-six to forty-eight 
hours to show germ tubes. Reddick deter- 
mined the incubation period on fruit as from 
eight to twenty-one days and found that only 
tender leaves still growing are susceptible. 
The berry is susceptible even after the calyx 
has fallen. The pycnidial spores are said by 
some to show a hyaline appendage ^^^ though 
others by careful study fail to find it.^'-*^ 
These spores often live over winter. ^^"^ The 
microconidia which develop in pycnidia similar 
to those of the macroconidia do not occur so 
abundantly early in the season as they do 
later and seem to be mainly limited to the 
fruits. Sporeless pycnidia, pycnosclerotia, also 
occur and may eventually develop into perithecia. Conidia on 
hyphse of questionable relationship to the fungus are sometimes 
seen. 

Reddick ^^" secured pure cultures in the following ways. 

1. In poured plate dilution of asci; some twenty days were 
required. 

2. By inverting a plate of sterile agar over a bunch of mature 
mummies floating on water. The ejected ascospores thus clung 
to the agar and gave pure cultures in ten days. 

3. By aseptic transfer of the mycelium. 

4. By aseptic transfer of pycnospores. 

Artificial infections have been reported in Europe from both 
conidia and ascospores: Reddick, who made many thousand in- 



FiG. 176.— G. bid- 
wellii; 26, nearly ma- 
ture ascus with 
spores; 27, mature 
ascospores; 28, ger- 
minating ascospores, 
29, same with ap- 
pressoria. After 
Reddick. 




242 THE FUNGI WHICH CAUSE PLANT DISEASE 

oculations under all conceivable conditions, failed utterly of posi- 
tive results. 

From the Caucasus Prillieux and Delacroix ^^^ have described a 
Guignardia causing a black rot of grapes which is regarded as 
distinct from the usual American form, differing both in the peri- 
thecial and conidial stages. This is called G. baccae (Cav.) Jacz. 
Its conidial form Phoma reniformis eventually covers the whole 
berry with pustules. Two kinds of pycnidia 
are described. 

G. vaccinii Sh.^^^- '^^ 

Perithecia on young fruit or flowers, sub- 
epidermal, globose, walls thick, carbonous; 
asci clavate, 60-80 n long; spores elliptic 
or subrhomboidal, hyaline, becoming tinted. 
/^^^ ^~~^^ Conidia (=Phyllosticta) borne in pycnidia 

Fig. 177.— A vertical sec- similar to the perithecia but thinner-walled, 
orSuiUrdL^vaccin™ 100-120 ^', conidia hyaline, obovoid, 10.5- 

showing asci. After 13 5 ^ 5.5 „ Qn Vacciuium. 
Shear. ^ 

In the decaying berries all sporing forms 
of the fungus are rare though in the softened tissues fungous 
hyphae abound. Transferred to culture media these hyphse grow 
readily and produce spores abundantly. 

The conidial form is common in artificial culture; the peri- 
thetical form comparatively rare. Pycnidia on leaves are sub- 
epidermal, usually hypophyllous, and are quite abundant. The 
spores at maturity issue in coils from the ostiole. 

The fungus was studied extensively in artificial culture by Shear, 
wet sterilized cornmeal proving a most suitable medium. Pycni- 
dia appeared in four to eight days after inoculation and spores were 
mature at twelve to eighteen days. Both pycnidia and perithecia 
were obtained in pure cultures. The rarity of cultures able to pro- 
duce perithecia is explained by Shear on the assumption "that 
there is some inherent potentiality in the mycelium of the fungus 
in certain strains, races, or generations which causes it to produce 
the ascogenous stage whenever conditions for its growth are favora- 
ble, i. e., on favorable culture media without special reference to 
their exact composition or environment or on the leaves of its nat- 
ural host." Conclusive infection experiments have not been made. 




THE FUNGI WHICH CAUSE PLANT DISEASE 243 

G. theae Bern. ^^^ grows on tea leaves. 

G. (Laestadia) buxi Desm. The perithecia develop on box 
leaves. It is probably saprophytic although sometimes considered 
a parasite. 

Stigmatea Fries (p. 236) 

Perithecia subepidermal, or subcuticular, thin, black; asci 
oblong, subsessile, 8-spored; spores ovoid-ellipsoid, 2-celled, yel- 
lowish or hyaline; paraphyses present. The 
ascigerous stage of two species of Entomo- 
sporium are said by Lindau to belong to 
this genus. Atkinson, however, places them in 
the genus Fabrea, see p. 149. 

S. juniperi (Desm.) Wint., on living leaves 
of Juniperus in Europe and America and on „ i -§_§(.• 
Sequoia in California. Asci and spores. 

After W inter 

Perithecia scattered, lenticular or subhemi- 
spheric, rough, 200-300 fi in diameter, asci rounded and obtuse 
above, abruptly tapering below into a short stipe, 60-70 x 20 /x; 
spores ovate-lanceolate, unequally 2-celled, yellowish-hyaline, 16- 
25 X 6-8 fi. 

S. alni occurs on alder leaves in Europe. 

Mycosphaerella Johans. (p. 236) 

Perithecia subepidermal, suberumpent, globose-lenticular, thin, 
membranous, ostiole depressed or short papillate; asci cylindric 
to clavate, 8-spored; spores hyaline or greenish, ellipsoid, 2-celled; 
paraphyses none. 

This large genus of over five hundred species formerly known as 
Sphserella contains several serious plant pathogens. It is often 
found in its conidial" forms as: Ramularia, Ascochyta, Septoria, 
Phleospora, Cercospora, Ovularia, Cylindrosporium, Phyllosticta, 
Graphiothecium, Phoma, Diplodia or Septogloeum. In many cases 
the relationship of the ascigerous and conidial forms is as yet but 
imperfectly known. The perithecia are usually found late in the 
season, often only on leaves that have borne the conidial stage in 
the summer and have then wintered. 



V. 



244 



THE FUNGI WHICH CAUSE PLANT DISEASE 



M. fragariae (Tul.) Lin.^" 

Perithecia on leaves, are produced late in the season, globose, 
subepidermal, membranous, black, thin-walled; asci few, clavate, 




Fig. 179. — Mycosphaerella fragarise. b, conidiophores burst- 
ing through the epidermis; c, arising from apex of a 
pyenidium; d, summer spores, one germinating; e, section 
of a spermogonium; /, section of perithecium; g, ascus 
containing eight two-celled spores. After Longyear. 

8-spored, 40 fx long; spores hyaline, 2-celled, with acute tips, 
15 X 3-4 /x. 

Conidia ( = Ramularia tulasnei) abundant in early summer on 
reddish spots, stromatic, conidiophores simple; conidia elliptic 
20-40 X 3-5 n, 2 to 3-celled. On Fragaria. 

The life history was first studied in 1863 by the Tulasne brothers 
under the name Stigmatea. The generic name was changed to 
Sphaerella in 1882 and later to Mycosphaerella. 



THE FUNGI WHICH CAUSE PLANT DISEASE 245 

The slender mycelium pervades the diseased areas disorganizing 
the host cells and resulting in reddish coloring of the sap. Ob- 
servations of Dudley ^^^ indicate that the mycelium or portions of 
it can remain alive over winter in the host tissue ready to produce 
abundant conidia in the spring. 

The most abundant conidial stage is the Ramularia-form 
(Fig. 179) which abounds all summer. Sowings of these conidia, 
under conditions of humid atmosphere, result in characteristic 
spots in from ten to eighteen days. Toward winter sclerotial 
bodies are formed from the mycelium. These in culture dishes 
have been seen to produce the typical summer conidia. Some of 
these sclerotia-like bodies have been reported as "spermogonia," 
bearing numerous "spermatia" 1 x 3 ;u. Perithecia abound in au- 
tumn. These are larger than the spermogonia and are usually 
embedded in the leaf tissue, though they sometimes appear super- 
ficially. Conidiophores are often borne directly on the perithecium 
wall. Ascospores germinate within the ascus. From the mycelium 
resulting from ascospores Dudley ^^^ observed the formation of 
typical summer conidia. 

M. grossulariae (Fr.) ^^^ 

Perithecia hypophyllous, gregarious, spherical, with minute 
ostiole, black; asci short-pedunculate, clavate, 55-66 x 8-12 fi; 
spores fusoid, filiform, curved or straight, uniseptate, hyaline, 
26-35 X 3-4 At. 

It has been reported on the gooseberry associated with Cer- 
cospora angulata and Septoria ribis. 

M.rubina (Pk.) Jacz.^oo 

Perithecia minute, gregarious, submembranous, obscurely papil- 
late, subglobose or depressed, erumpent, black; asci cylindric, 
subsessile, 70-80 x 10-12 ^t; spores oblong, obtuse, uniseptate, 
generally constricted in the middle, 15 x 6-7 fx, upper cell broadest. 

Conidia ( = Phoma) are associated with the perithecia and are 
supposed to be genetically connected with them as is also a second 
spore form ( =Coniothyrium). 

The species is held responsible for bluish-black spots on rasp- 
berry canes. 

M. cerasella Aderh.^''^ is reported as the perithecia! stage of 
Cercospora cerasella common on cherry. 



246 



THE FUNGI WHICH CAUSE PLANT DISEASE 




Fig. 180. — M. sentina, yeptoria stage. 
Portion of a section through a pear leaf 
spot, showing e, e, epidermis; p, pali- 
sade cells sp, spongy parenchyma; a, 
S. piricola pycnidium, giving out 
spores, b. After Longyear. 



M. sentina (Fr.) Schr. 

Perithecia, 80-110 n; on dead spots of leaves, the long ostiole 
erumpent; asci clavate, 60-75 x 11-13 /jl, colorless; spores fusiform, 

curved or straight, 26-33 x 
4)u. 

Conidia (=Septoria piricola) 
borne in pycnidia which are 
similar in size and form to the 
perithecia; conidia filiform, 
curved, 3-celled, 40-60 x 3 ju- 
On pear and apple. 

The conidial form was men- 
tioned in America as early as 
1897 by Atkinson ^04 and was 
the subject of a comprehensive 
bulletin by Duggar in 1898.203 
The ascigerous stage was demon- 
strated by Klebahn in 1908.202 
The pycnidia, mainly hypophyllous, are sunk deeply into the 
leaf tissue and are surrounded by a delicate pseudoparenchyma. 
The conidia are distinctly tinted, green or smoky. 

The perithecia are numerous, and crowded on grayish spots, 
hypophyllous, on old wintered leaves. They are without stroma. 
Klebahn by inoculations (June, 1904) with ascospores secured 
spots in fifteen days and pycnidia in twenty- 
nine days, bearing the characteristic conidia. 
From ascospores he also made pure cultures 
which soon developed pycnidia with conidia. 
Pure cultures made from conidia in the hands 
of both Klebahn and Duggar have failed to 
give typical perithecia. 
M. citrullina (C. 0. Sm.) Gros. 
Perithecia roughish, dark-brown or black, 
depressed-globose to inverted top-shaped, 
usually with a papillate ostiole, densely 
scattered, erumpent, 100-165 n; asci cylindric to clavate, 45-58 x 
7-10 ft; spores hyaline, oblong-fusoid, constricted at the sep- 
tum. 




Fig. 181.— M. sentina. 
Conidial layer, co- 
nidiophores and co- 
nidia. After Kle- 
bahn. 




THE FUNGI WHICH CAUSE PLANT DISEASE 247 

Conidia ( = Diplodina citrullina) Pycnidia similar to the peri- 
thecia, spores 2-celled, hyaline, straight or curved, more or less 
cylindric, 10-18 x 3-5 fx. 

The fungus was isolated in pure culture by Grossenbacher ^°^ 
from muskmelons by direct transfer of diseased tissue to potato 
agar. Inoculations from these cultures proved the fungus capable 
of entering healthy uninjured tissue, the • 

disease showing about six days after in- 
oculation. The brownish pycnidia origi- 
nate from an extensive subepidermal, 
partially cortical, much-branched, brown- 
ish mycelium but soon break through and 

, , r • 1 iTTi • Fig. 182. — M. sentina. .4, 

appear almost superhcial. When mois- perithecium and asci. Af- 
tened, spores issue in coils. Darker peri- *'^'' Kiebahn. 
thecia, nearly superficial, are found on old diseased spots. Both 
ascospores and conidia are capable of causing infection. Inocu- 
lations on pumpkin and watermelon gave positive results; these 
on cucumber, West Indian gherkin, squash, pumpkin, and gourd 
were negative. The same fungus has been reported as cause of 
canker of tomatoes.'"^ 

M. tabifica (P. & D.) Johns.^o^'^io 

Perithecia rounded, brown; asci oblong-clavate, 8-spored; spores 
hyaline, upper cell larger, 21 x 7.5 /jl. 

Pycnidia (=Phoma) subglobose; conidia elliptic, hyaline, 5-7 x 
3.5 fjL, escaping as a gelatinous cirrus. 

This conidial form, common on beets causing leaf spot through- 
out the summer, is said by Prillieux and Delacroix to be connected 
with M. tabifica the perithecial form, which is found upon the 
dead petioles at the end of the season. Convincing evidence ^°^ of 
this connection seems wanting. The conidial stage ^"^ is variously 
known as Phoma betae, Phoma sphserosperma, Phyllosticta 
tabifica. The Phoma-form from stems and rotten roots and the 
Phyllosticta-forms from leaves were both studied by Hedgcock ^^^ 
in pure cultures on many media and many inoculations were made, 
all leading to the conclusion that the Phoma and the Phyllosticta 
are identical. 

M. tulasnei Jacz.-^^ 

Perithecia subglobose, minute; asci cylindric fusoid; spores 



248 



THE FUNGI WHICH CAUSE PLANT DISEASE 



oblong, rather pointed, upper cell in the ascus somewhat larger 
than the others, 28 x 6.5 n. 

Conidia of two kinds, (1) (=Cladosporium herbarum) tufts 
dense, forming a velvety blackish-olive, effused patch, conidio- 
phores erect, septate, rarely branched, often nodose or keeled; 
conidia often in chains of 2 or 3, subcylindric pale-olive, 1 to 
3-septate, 10-15x4-7 fx. (2) ( = Hormodendrum cladosporioidies 
Sacc.) Hyphse erect, simple, bearing apically or laterally a tuft 





Fig. 183. — M. citrullina, A. pycnidium (Diplodia) in sec- 
tion, B, perithecium ; C, ascus and spores. After Grossen- 
bacher. 



of small, elliptic, continuous, brown conidia in simple or branched 
chains. 

It is the cause of serious disease in Europe, being especially 
injurious to cereals after a rainy season preceded by a drought 
and is found also parasitic on pea, apple, raspberry, cycad, agave 
and as a saprophyte almost anywhere. 

M. stratiformans Cobb, affects sugar cane. The perithecial 
stage alone is known. ^^^ Further study is desirable. 

M. gossypina (Cke.) Er.^^^"-^^ 

Perithecia ovate, blackish, partly immersed, 60-70 x 65-91 mJ 
asci subcylindric, 8-10 x 40-45 n; spores elliptic to fusoid, con- 
stricted at the septum, 3-4 x 15-18 /x. 

Conidia (=Cercospora gossypina); hyphae flexuose, brown, 



THE FUNGI WHICH CAUSE PLANT DISEASE 249 

120-150 n high; conidia attenuate above, 5 to 7-.septate, hyahne, 
70-100 X 3 M- On cotton. 

The intercellular mycelium is irregular, branched, septate, and 
produces tuberculate stromata from which the brownish hyphae 
arise. The perithecia, much less common, are partly immersed 
in old leaves. 

M. morifolia (Fcl.) Ljn. in its conidial stages, Cylindrosporium 
mori and Septogloeum mori, affects Morus. 

M. maculiformis (Pers.) Schr. grows on many trees. Especially 
common are its conidial stages Cylindrosporium castinicolum and 
Phyllosticta maculiformis. 

M. rosigena E. & E. -^8-219 

Amphigenous on reddish-brown, purple-bordered spots which 
are about 3-4 mm. in diameter; perithecia thickly scattered over 
the spots, minute, 60-75 n, partly erumpent, black; asci sub- 
clavate to oblong, 25-30 x 8-10 ix; spores biseriate, clavate- 
oblong, hyaline, 1-septate, 10-12 x 2 ju, ends subacute. 

It causes leaf spots of rose in America. 

M. brassicaecola (= Phyllosticta brassicaecola) grows on cabbage. 

M, punctiformis Pers. produces leaf spot on oak, lime, hazel; 

M. fagi Auser. on beech; 

M. pinifolia Due. on pine leaves; ^°^ 

M. abietis (Rost.) Lin. a leaf disease of balsam.^^" 

M. taxi Cke. grows on yew; 

M. hedericola t)esm. on Hedera leaves; 

M. gibelliana Pass, on Citrus leaves; 

M. vitis Fcl. on grape leaves; 

M. elasticae Kr. ^-^ on Ficus elastica. 

M. cydoniae Vogl. ^"^ on quince is probably identical with 
M. sentina on pear and apple. 

M. ulmi Kleb. occurs on elm with its conidial forms, a Phleo- 
spora and Phyllosticta bellunensis. 

M. comedens Pass, is on the same host. 

M. larcina Hart, and its conidial form Leptostroma larcinum 
affect larch, causing defoliation. 

M. loefgreni N. on oranges and M. coffeae N. on coffee are 
tropical forms. 

M. populi Schr. (=Septoria populi) is on Populus.^"* 



250 THE FUNGI WHICH CAUSE PLANT DISEASE 

M. pinodes Berk & Blox. 

Perithecia numerous, 100-140 /x; asci oblong-cylindric, 58-62 x 
12 ju; spores 2-rowed, 14-16 x 5. 

Pycnidia (=Septoria pisi), with large ostiole; spores 35-45 x 3- 
3.5 fx, 1 to 3-septate. On pea stem and leaves.^°^' ^^^ 

M. primulae is on primrose; 

M. tamarindi on tamarinds in Africa. 

M. cinxia Sacc. is on lilies, causing leaf blight; 

M. fusca Pass, on the gladiolus; 

M. coffeicola on coffee in Mexico. 

M. shiraina Miy. and M. hondai Miy. are on rice. 

M. convexula (Sch.) Rand. 

Perithecia hypophyllous, gregarious or scattered, finally erum- 
pent, 100-200 /x in diameter, papillate at maturity; no paraphyses; 
asci fasciculate, 54-100 x 9-11 n, 8-spored; spores allantoid, 
1-septate, hyaline, 13-27 x 3.5-5.5 /x. 

Forming a leaf spot on pecans.^^^ 

An undetermined species of Mycosphaerella has been reported 
on the grape by Rathay.^^^ 

Many other species are known on ferns, cereals, lilies, and va- 
rious trees and herbs. 

In the genus Pharcidia. P. orzas Miy. is on rice.^°^ 

In Sphaerulina the species Sphaerulina taxi Mass. is injurious on 
yew leaves. 

Pleosphaerulina Passer (p. 236) 

Perithecia subepidermal, erumpent, small, globoid or lenticular, 
black; asci 8-spored, clavate; spores muriform, hyaline; paraphyses 
none. 

P. briosiana Pol. causes a leaf disease of alfalfa in Italy. 

Pleosporaceae (p. 223) 

Perithecia sunken, at length erumpent, or from the first more 
or less free, membranous or coriaceous, usually papillate; asci 
clavate-cylindric, double-walled; spores variable, but usually 
colored, oblong, fusoid or elliptic; paraphyses present. 

An order of some nineteen hundred species most of which are 
saprophytes, although several are parasites, some of considerable 
importance. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



251 



Key to Genera of Pleosporaceae 

Spores 1-celled 

Spores with blackish appendages, elon- 
gate, hyaline 1. Urospora. 

Spores unappendaged 

Spores elongate, hj^aline or light yel- 
low 2. Physalospora, p. 252. 

Spores elongate, fusoid, hyaline; tips 

bent 3. Therrya. 

Spores 2-celled 

Spores with the 2 cells very unequal in 
size 
Upper cell the smaller; parasitic on 

Riccia 4. Arcangelia. 

Basal cell the smaller; saprophytes. ... 5. Apiospora. 
Spores with both cells about equal 

Perithecia hairy; spores hyaline or 

brown 6. Venturia, p. 253. 

Perithecia smooth 

Spores hyaline 7. Didymella, p. 255. 

Spores brown 

Perithecia not stromatic 8. Didymosphaeria, p. 256. 

Perithecia borne on a stroma 9. Gibbellina, p. 256. 

Spores more than 2-celled 

Spores elongate, with cross walls only 
Spores appendaged 

Spores clavate, 4 to 6-celled, brown, 
the basal cell hyaline long- 

appendaged 10. Rabentischia. 

Spores filiform, many-celled, with 

filiform appendages 11. Dilophia, p. 257. 

Spores not appendaged 
Spores fusoid or elongate, blunt, never 
filiform or separating into cells 
Spores elongate, 3 to many-celled, 
hyaline or brown 
Spores with a thick, dark-brown 
epispore and a thin hj^a- 
line endosporc, 4-celled, el- 
lipsoid 12. Chitonospora. 



252 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Spores not as above, elongate 
3 to many-celled hyaline or 
brown 

Perithecia hairy 13. Pocosphaeria. 

Perithecia smooth 

Spores hyaline 11. Metasphaeria, p. 257. 

Spores yellow or dark- 
brown 15. Leptosphaeria, p. 257. 

Spores fusoid, 7 to many-celled, 
the central cell enlarged and 

brown, the rest hyaline IG. Heptameria. 

Spores fusoid, up to 30-celled hya- 
line or brown 17. Saccardoella. 

Spores filiform, often separating into 
cells 

Perithecia hairy 18. Ophiochaeta. 

Perithecia smooth 19. Ophiobolus, p. 259. 

Spores muriform 
Asci 8-spored 

Spores appendaged 20. Delacourea. 

Spores not appendaged 

Perithecia hairy.. 21. Pyrenophora, p. 262. 

Perithecia smooth 22. Pleospora, p. 259. 

Asci 16-spored 23. Capronia. 



Physalospora Niessl. (p. 251) 

Perithecia subglobose, covered, membranous, or coriaceous, 

black, with the ostiole erum- 
pent; asci clavate-cylindric ; 
spores ovoid or oblong, con- 
tinuous, hyaline or subhya- 
line; paraphyses present. 

This genus contains over 
one hundred thirty species, a 
few of which are parasitic on 
twigs and leaves. Some spe- 
cies possess a Gloeosporium 
as the conidial form. 
gregaria and its conidial stages Tetradia saficicola and 




Fig. 184. — Physalospora. Perithecia and 
ascus. After Winter. 



THE FUNGI WHICH CAUSE PLANT DISEASE 253 

Macrodendrophoma salicicola cause black cankers on oziers in 
Ireland.22^ 

P. abietina P. & D.-^ is found on Picea; P. cattleyae Maub, & 
Las. in its conidial form, Gloeosporium macropus--^ parasitizes 
Cattleya. P. laburni Bon. is on Cytisus. 

P. woronini M. & F. is described as causing a disease of grapes 
in the Caucasus. ^^'' 

P. vanillae Zimm. is on vanilla; 

P. fallaciosa Sacc. on banana leaves. 

Venturia Cesati & de Notaris (p. 251) 

Perithecia superficial or erumpent, bristly, ostiolate, membra- 
nous, dark colored; asci sessile or short stipitate, ovate or saccate; 
spores oblong to ovoid elliptic, hyaline or yellowish; paraphyses 
usually none. 

The conidial stages in some cases belong to the form genus 
Fusicladium and constitute the parasitic portion of the life history 
of the fungus, the ascigerous form usually being limited to old or 
wintered parts of the host. 

There are over fifty species, several of which cause diseases. 

T7- «;^;^« A 1 \ 230, 312, 313, 350 

V. pinna Aderh. ' 

Perithecia gregarious, smooth or bristly, globoid, 120-160 /x; 
asci cylindric; spores unequally 2-celled, yellowish-green, 14-20 x 
5-8 M- 

Conidia ( = Fusicladium pirinum) effused, velvety, blackish-ohve, 
conidiophores short, wavy or knotted, thick- walled; conidia ovate 
fusoid, olive, becoming 1-septate with age, 28-30 x 7-9 fji. 

It is found on the pear wintering in perithecial form on leaves, 
and in conidial form, or as mycelium on twigs. 

V. inaequalis (Cke.) Aderh. (=V. pomi [Fries] Winter). 

Perithecia globose, short-necked, 20-160 /x, smooth or bristly 
above; asci cylindric, 40-70 fjL long; spores yellowish-green, un- 
equally 2-celled, upper cell shorter and broader, 11-15 x 4-8 /i. 

Conidia ( = Fusicladium dendriticum) effused, velvety, forming 
dendritic patches of compact masses of erect closely septate 
brown mycelium; conidiophores closely septate, brown, 50-60 x 
4-6 /x, wavy or nodulose; conidia sohtary, terminal, obclavate. 



254 THE FUNGI WHICH CAUSE PLANT DISEASE 




Fig. 185.— V. insequalis. A, portion of a section through a scab spot on apple; b, spread- 
ing under and hfting the cuticle, a; c, partly disorganized cells of the apple; e, healthy 
cells of the apple. B, two conidiophores with summer spores /. C, spores ger- 
mmating. D, portion of a section showing a perithecium and asci. E, two asci, each 
containing 8 two-celled spores, three of which are shown at F. After Longyear. 



THE FUNGI WHICH CAUSE PLANT DISEASE 255 

yellowish-olive, continuous when young but at length septate, 
30 X 7-9 M- 

Its hosts are apple and other pomaceous fruits except the pear. 
Conidia of special form have been known under the name Napi- 
cladium soraueri. 

The two last conidial forms have been long regarded as identical 
and are found in literature as Fusicladium dendriticum. The 
olive-green mycelium in both cases grows subepidermally in the 
leaf and fruit killing the epidermis and forming subepidermal 
stromata from which conidiophores are produced. Stromatal 
development is also said to be often subcuticular, resulting in a 
separation of the cuticle from the epidermis. 

The conidia are produced apically on short stalks and as each 
conidium is cut off the conidiophore grows forward, leaving scars 
equal in number to the conidia produced. Pycnidia have been 
reported on the mycelium in twigs in winter. ^^^ 

Perithecia first form on the lower leaf surface in October and 
mature in April. They are most abundant when protected by 
sod or piles of leaves, and appear as small black pustules often 
on grayish spots. Their comiection with the conidial stage was 
first shown by Aderhold ^^^ and confirmed by Clinton. ^^^ 

The fungus from apple was cultured on apple-leaf-agar by Clinton. 
Pure colonies developed in 4 to 5 days and infection was secured 
on leaves. Cultures from ascospores gave rise to typical conidia. 

V. crategi Aderh. occurs on Crataegus. 

V. cerasi Aderh. ( = Fusicladium cerasi) is found on cherries. 
Aderholt -^^ demonstrated the connection between the ascigerous 
and conidial forms. 

V. ditricha (Fr.) Karst. (= Fusicladium betulae) is found on 
birches; V. tremulae Aderh. (= Fusicladium tremulse) on aspen; 
V. fraxini Aderh. ( = Fusicladium fraxini) on ash; 

V. inaequalis var. cinerascens Lin. (= Fusicladium orbiculatum) 
on Sorbus. 

Didymella Saccardo (p. 251) 

Perithecia covered, membranous, globose-depressed, minutely 
papillate; black; asci cylindric or clavate* spores ellipsoid or 
ovate, 2-celled, hyaline; paraphyses none. 



256 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Of the some one hundred twenty species D. citri N. is of in- 
terest since it forms cankers on orange trees in Brazil. 

Didymosphaeria Fuckel (p: 251) 

Peritheeia immersed, later erumpent; asci cylindric to clavate, 
8-spored; spores elliptical to ovate, 2-celled, brown. 

This genus differs from Didymella chiefly in the dark-colored 
spores. It contains some one hundred twenty species and has 
occasional parasitic representatives on leaves and twigs. 






Fig. 186.— Didymella. A, 
ascus; B, hymenium of 
a pycnidium. After 
Brefeld. 



Fig. 187. — Didymo- 
sphseria. C, an as- 
cus; D, c o n i d i o- 
phore and conidia. 
After Brefeld. 



Fig. 188. — Dilo- 
p h i a graminis. 
J, ascus; K, 
spore. After 
Winter. 



D. sphaeroides (Pers.) Fr. is. on Populus leaves in Europe. 

D. catalpae.^^^ 

Peritheeia very small, scattered, embedded in the tissue of the 
leaf, pyriform to nearly spherical, varying in width from 48-104 fj. 
and in depth from 64-140 /x; ostiole broadly conical, erumpent; 
asci 8-spored, cylindrical, usually somewhat curved; paraphyses 
few or wanting; spores oblong-elliptical, hyaline or yellowish, 
uniseptate, constricted in the middle, 9.6-13 x 3-4 /j,. On Catalpa. 

D. populina Vuill., causes death of poplars in Europe.^^"* 

D. epidermidis Fr. is found on Berberis, Sambucus and Salix. 

Gibbellina Passerina (p. 251) 

Stromata black, sunken in the substratum, formed of thin, closely 
interwoven hyphse; peritheeia sunken in the stromatn, globose; 



THE FUNGI WHICH CAUSE PLANT DISEASE 257 

asci elongate-globoid; spores elongate, 2-celled, brown; paraphyses 
present. Genus of one species. 

G. cerealis Pers. causes a serious grain disease in Europe, es- 
pecially of wheat in Italy. -"^'^ 

Dilophia Saccardo (p. 251) 

Perithecia sunken, not erumpent, delicate, dark-colored, ostiole 
papillate; asci long-cylindric; spores elongate- fusiform to filiform, 
multicellular, each end appendaged, the appendages hyaline, the 
spores hyaline or yellow. Fig. 188. 

There are three species, one of which D. graminis (Fcl.) Sacc. 
parasitizes rye and wheat in Europe. The conidial form Dilo- 
phospora graminis Desm. is especially common, 

Metasphaeria Saccardo (p. 252) 

Perithecia clavate, sunken in a stroma, at first covered ; leathery, 
dark, with ostiole; asci cylindric to clavate, 8-spored; spores ellipsoid, 
elongate, blunt or appendaged, 3 to many-celled; paraphyses filiform. 

M. albescens Thum. is on rice in Japan. 

Leptosphaeria Cesati & de Notaris (p. 252) 

Perithecia at first subepidermal, at last more or less erumpent, 
subglobose, coriaceo-membranous, globose, ostiole usually papil- 
late; asci subcylindric; spores ovoid, oblong or fusoid, two or more 
septate, olivaceous, yellowish or brown. 

There are about five hundred species, many of which in the 
conidial forms embrace Cercospora, Phoma, Hendersonia, Sporides- 
mium, Septoria, Coniothyrium or Cladosporium. 

L. coniothyrium (Fcl.) Sacc.^^'*' ^^^ 

Perithecia gregarious, subepidermal, depressed, globose, black; 
ostiole papillate, erumpent; asci cylindric, stipitate, 8-spored, 
66-96 X 4-6 n; spores 1-rowed, oblong, 3-septate, constricted, 
fuscous, 10-15 X 3.5-4 /x. 

Pycnidia (= Coniothyrium fuckelii), similar to perithecia; spores 
ovate, continuous, .fuscous. 

It occurs on black and red raspberries and numerous other hosts. 

Stewart ^^^ verified the assumed identity of the conidial form 
with this ascigerous fungus by pure culture studies. 



258 



THE FUNGI WHICH CAUSE PLANT DISEASE 



L tritici (Gar.) Pass ^^^ (=Pleospora tritici). On wheat.^^^ 
Perithecia innate, globose, black, papillate; asci clavate, short- 

stipitate, 8-spored; paraphyses filiform, 48-50 x 15-16 n; spores 

2-seriate, round, fusoid, 3-septate, constricted, pale, 18-19 x 4.2- 

5.5. 
L. herpotrichoides d. Not.^^^ parasitizes rye causing the stalks 

to break at the nodes; 





Fig. 189. — Cross-section of raspberry bark showing 
two perithecia of L. coniothyrium at the top, A, and 
two pycnidia of Coniothyrium fuckelii, at the bot- 
tom, B. 4. An ascus of L. coniothyrium. 5. Spores 
of L. coniothyrium. After Stewart. 

L. sacchari V. B. d H. occurs on sugar-cane. 

L. napi (Fcl.) Sacc. (=Sporidesmium exitiosum) is found on 
rape; L. phlogis Bos. (=Septoria phlogis) on Phlox; 

L. circinans (Fcl.) Sacc. kills alfalfa roots, potato, clover, beets 
and other hosts; -^^ 

L. vitigena Schul. occurs on grape tendrils; 

L. stictoides Sacc. on Liriodendron; L. rhododendri on Rho- 
dodendron ; 

L. iwamotoi Miy. on rice; 



THE FUNGI WHICH CAUSE PLANT DISEASE 



259 



L. taxicola R. K. on Taxus canadensis; 
L. vagabunda Sacc. spots linden branches, 
is perhaps Phoma tilise.-^^ 



Its conidial form 



Ophiobolus Riess (p. 252) 

Perithecia scattered, subglobose, submembranous, covered or 
suberumpent, ostiole papillate or elongate; asci cylindric; spores 
fusiform, hyaline or yellowish. 



Fig. 190. — Ophio- 
bolus. B, asfus; 
C, spore. After 
Lindau and Win- 
ter. 




Fig. 191. — Pieospora from 
passion-fruit. The spores 
are just beginning to ger- 
minate, the end cells start- 
ing first. After Cobb. 



A genus of some one hundred twenty-five species. 
O. graminis Sacc. and O. herpotrichus Sacc. occur on grasses 
and are quite injurious in Europe. ^^'^ 
O. oryzeae Miy. is found on rice.^"'' 



Pieospora Rabenhorst (p. 252) 

Perithecia covered at first, later more or less erumpent, usually 
membranous, black, globose; asci oblong to clavate; spores elon- 
gate or ovate, muriform; paraphyses present. 



260 THE FUNGI WHICH CAUSE PLANT DISEASE 

Conidia occur as Macrosporium, Alternaria, Cladosporium, 
Sporidesmium, Phoma, Helminthosporium. 

There are over two hundred twenty-five species, mostly sap- 
rophytic. Many conidial forms whose connection to this genus 
have not yet been definitely proved probably belong to it and are 
in many instances parasites. 

P. tropeoli Hals, is reported as the cause of disease of the cul- 
tivated Nasturtium. ^'^'^ 

Perithecia pyriform, 140-160 /x; asci oval, one-sided, spores 
hyaline or very light-olivaceous, 25-35 x 6-8 fx. 

The Alternaria-form was grown from the ascospores by Halsted 
and from the Alternaria spores, grown in pure culture, perithecia 
were obtained in about twelve days. 

P. albicans Fcl. occurs on chicory as Phoma albicans; 

P. hyacinthi Sor. on hyacinths with its conidia as Cladosporium 
fasciculare; P. hesperidearum Cotton, in its conidial form, Spori- 
desmium pyriforme, causes a black mold on oranges. 

P. herbarum (Pers.) Rab. (conidia= Macrosporium commune) 
is a common saprophyte which sometimes becomes parasitic. 

P. pisi (Sow.) Fcl.^^^ is found on the garden pea; 

Perithecia and spores as in P. herbarum but spores more narrow. 

P. ulmi. Fr. causes an elm leaf spot. P. infectoria Fcl. a com- 
mon saprophyte, parasitizes tobacco. 

P. oryzae Miy. is on rice; 

P. negundinis Oud. is injurious to nursery stock of Negundo; 

P. putrefaciens (Fcl.) Fr. (conidia = Sporidesmium) is on carrots. 

Pleosporae on grains.'-^^' ^^^ 

Several species of Pleospora with their attendant conidial forms 
of Helminthosporium and Alternaria are known on various grains 
and grasses. Cross inoculation experiments have shown here 
biologic specialization similar to that encountered among the 
Erysiphese, in that conidia or ascospores from one host usually 
give negative results on host species other than that on which they 
grew. Thus Diedicke ^^^ says the Pleospora of Bromus cannot 
be grown on Triticum repens nor on cultivated barley or oats. 
Helminthosporium was formerly thought to be the conidial stage 
of all of these grain Pleosporas, but recent work of Diedicke shows 
that one form which he regards as P. trichostoma (Fr.) Wint. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



261 



22 



possesses an Alternaria conidial form. Following Diedicke, the 
forms given below would be recognized. 

P. bromi Died. 

Perithecia brown, hairy; asci 189-288 x 34-59 n, saccate, thin- 
walled; spores 2-seriate, golden-brown, 4-xelled, 48-83 x 19-33 fx. 

Conidia ( = Helminthosporium bromi) on brownish spots, 108- 
150 X 13-20 M, 5 to 7-celled, dark colored. On Bromus. 

P. gramineum Died. 

Conidia (=Helminthosporium gramineum); conidiophores short, 
subflexuose, light-brown; conidia solitary, elongate-cylindric, 4 to 
7-celled, 15-19 n wide and of variable length. 

The mycelium invades the tissue causing long brown spots. 
These later become covered with an abundance of conidiophores 
which emerge through the stomata. Potter also reports in- 
vasion and complete occupation of ovaries by the mycelium 
Sclerotia-like bodies are 
formed on leaves and 
stems. They were first 
seen in artificial cul- 
tures of the fungus by 
Ravn ^^^ and have been 
since found in nature 
(Noack2«). 

The conidiospores 
have been shown to be 
long-lived, and spring 
infection begins largely 
from conidia carried 
over winter on seed. 
Extensive study was made of the conidial form by Ravn who 
found the mycelium to be of two kinds, one aerial and hyaline, 
the other strict and dark. It grew well on acid or neutral media. 

Careful infection experiments (Ravn) proved the pathogenicity 
of H. graminum for barley but showed it incapable of infecting 
oats, rye or wheat. 

Ravn regards the disease produced by H. gramineum as often 
general, not local, in that the mycelium may invade the growing 
points, resulting in infection of all the leaves. 




Fig. 192.^— p. trichostoma. 1, group of asci, 2, a 
singlo spore at the apex of an ascus. After 
Diedicke. 



262 THE FUNGI WHICH CAUSE PLANT DISEASE 

P. tritici-repentis Died, is found on Triticum repens (=Agropy- 
ron repens.) Conidia=Helminthosporium tritici repentis. 

P. trichostoma (Fr.) Wint. ( = Pyrenophora trichostoma (Fr.) 
Sacc.242 

Perithecia gregarious, innate, conical, black, ostiole surrounded 
by black hairs, which are simple, septate, 6-8 fx in circumference; 
asci clavate 300 x 40 /x; spores broadly oblong, obtuse, unequally 
4 to 6-septate, muriform, brownish, 52 x 20 m; paraphyses branched. 

On rye with the conidial form =Alternaria trichostoma Died. 

In the present state of our knowledge little is to be gained by 
recognition of these purely "biologic species," and all the forms 
may be grouped under the name P. trichostoma, recognizing the 
fact that it shows biologic differentiation. 

Two hypothetical forms P. teres Died, and P. avense Died, 
pertain to Helminthosporiums of corresponding names. 

Massariaceae (p. 223) 

Stroma none; perithecia separate, sunken, not erumpent, open- 
ing by a small pore, leathery or carbonous, compact; spores usually 
surrounded b}^ a jelly-like substance; paraphyses present. 

This family of ten genera and about one hundred twenty-five 
species contains only one parasite of interest. 

Key to Genera of Massariaceae 

Spores 1-celled 

Spores not surrounded by a jelly-like sub- 
stance 1. Enchnoa. 

Spores surrounded by a jelly-like sub- 
stance 2. Pseudomassaria. 

Spores several-celled 
Spores not muriform 
Spores hyaline or yellow 

Spores ellipsoid to spindle-shaped, 

several-celled, hyaline 3. Massarina. 

Spores spindle-formed, curved, 3 to 4- 

celled, yellow 4. Ophiomassaria. 

Spores 2 to 4-celled, elongate, hya- 
line 5. Charrinia, p. 263. 



THE FUNGI WHICH CAUSE PLANT DISEASE 263 

Spores brown 
Spores 2-celled 

Perithecia scattered irregularly. . . G. Phorcys. 

Perithecia in circular clusters 7. Massariovalsa. 

Spores more than 2-celled 

Spores ellipsoid to si)indle-shaped, 

many-celled 8. Massaria, p. 263. 

Spores cylindric, bent, S-celled. . . 9. Cladosphaeria. 
Spores muriform 10. Pleomassaria. 

Massaria theicola Peteh invades the ducts of the tea plant. The 
genus Charrinia is said by Viala & Ravaz -^'^ to contain the ascige- 
rous form of Coniothyrium diplodiella (Speg.) Sacc. 

Gnomoniaceae (p. 223) 

Perithecia sunken, Avith an elongate, cylindric, beak-like ostiole, 
rarely with a papillate one; leathery or membranous, rarely borne 
on a stroma; asci mostly thickened apically and opening by a pore; 
spores hyaline ; paraphyses usually absent. 

A family of about one hundred fifty species; four genera con- 
tain important pathogens. 

Key to Genera of Gnomoniaceae 

Spores 1-celled 

Mouth of the perithecium short 

Asci cylindric, 8-spored 1. Phomatospora. 

Asci clavate, 2-spored 2. Geminispora. 

Mouth of the perithecium elongate, beak- 
like 
Mouth of the perithecium straight 

Asci many-sporcd 3. Ditopella, p. 264. 

Asci 8-spored 

Spores ellipsoid or fusoid 

A clypeus present 4. Mamiania. 

Stroma present 5. Glomerella, p. 264. 

Stroma absent 6. Gnomoniella, p. 273. 

Spores elongate fusoid, or filiform 7. Cryptoderis. 
Mouth of the perithecium recurved ... 8. Camptosphaeria. 



--^ 



264 THE FUNGI WHICH CAUSE PLANT DISEASE 

Spores 2 or more-celled 
Asci 8-spored 

Spores elongate, 2 to 4-celled 9. Gnomonia, p. 274. 

Spores fusiform, curved, 2-celled 10. Hendersonia. 

Asci many-spored; spores elongate, 
2-celled 

Perithecia beaked 11. Rehmiella. 

Perithecia not beaked 12. Rehmiellopsis, p. 276. 

Ditopella de Notaris (p. 263) 

Perithecia corticolous, covered, globose or somewhat depressed, 
ostiole suberumpent; asci subclavate, polysporous; spores oblong 
or fusoid, continuous, subhyaline; paraphyses none. 

D. ditopa (Fr.) Schr. causes death of oak twigs in Europe; 

D. fusarispora d. Not., occurs on alder in Europe. 

Glomerella Spaulding & von Schrenk -«-• ^'~ (p. 263) 

Perithecia cespitose, membranous, dark brown, rostrate, of a 
lighter color at the apex in early stages, flask-shaped, hairy, on 
or immersed in a stroma; asci sessile, clavate; spores 8, hyaline, 
oblong, 1-celled, slightly curved, elliptic; paraphyses usually none. 
Conidia=in part Colletotrichum and Gloeosporium. 

This genus was first described by Stoneman, from perithecia 
obtained from cultures of the conidia,"'^^ as Gnomoniopsis. On ac- 
count of preoccupation it was renamed Glomerella by Spaulding and 
von Schrenk -"^^ in 1903. Studies by Shear have shown that there 
is much variation in pure line cultures both from ascospores and 
from conidiospores.-^^ This leads to great uncertainty as to spe- 
cific limitations as will become apparent in the paragraphs below. 
The conidial forms are very common and are usually parasitic. 
The ascigerous stages are comparatively rare. Sometimes they 
are found in nature; again only in artificial culture. Some forms 
known to be ascigerous may in one culture yield abundant peri- 
thecia while other cultures of the same fungus may persistently 
refuse to bear asci at all. 

G. rufomaculans (Berk.) S. & S.^^O'-^^ 

Perithecia on decaying fruits, subspherical, more or less grouped; 



THE FUNGI WHICH CAUSE PLANT DISEASE 



265 




asci subclavate, fugaceous, 55-70 fx; ascospores allantoic!, 12- 
22 X 3-5 fi] conidial stage (=Gloeosporium rufomaculans) with 
small sori, developing in more or less concentric circles, usually 
soon rupturing and pushing out spores in small pinkish masses; 
spores hyaline to greenish, 
chiefly oblong, unicellular 10- 
28 X 3.5-7 fx. 

The conidial stage of this 
fungus was first described by 
.Rev. M. J. Berkeley in 1854 
as a Septoria. It was later 
transferred to the form genus 
Glceosporium under which 

name the literature pertaining Fig- 193.— ?. perithecium of G. rufomacu- 
lans showing asci in situ; 6, asci show- 
to it is largely to be found. ing detail. After Spaulding and von 

See Southworth.2^0 The as- ^'^'^''^■ 

cigerous stage was found by Clinton -""^ in 1902 and the fungus 
described as a Gnomoniopsis. In 1903, it was given the present 
name. A bibliography of some one hundred eighty titles is 
given by Spaulding and von Schrenk.^^^ 

The conidia germinating on apples send germ tubes through 
the skin, usually through wounds, occasionally through a sound 
surface. -'^^ The myceHum grows subepidermally, branching 
rapidly, intercellularly and intracellularly, 
absorbing the sugar and other nutrients 
present, and resulting in brown discolora- 
tion of cells and dissolution of their connec- 
tion with neighboring cells. The mycelium 
is first hyaline but later, especially in the 
stromata, it ma}^ be quite dark. Acervuli 
soon appear, often in concentric rings, lift- 




FiG. 194. — G. cactorum. 
Appressoria produced 
by germinating spores. 



After Spaulding and ing the epidermis with their palisades of 
conidiophores. The latter, at first hyaline, 
later olivaceous, bear the numerous conidia, which are pinkish, 
rarely cream-colored, in mass. In germination the conidia be- 
come uniseptate and often on the tips of the young mycelium 
develop the dark thick-walled irregularly shaped spore-like struc- 
tures, so common on the sporelings of the Melanconiales. These 



266 



THE FUNGI WHICH CAUSE PLANT DISEASE 



structures are regarded by Hasselbring -^- as organs of attachment 
to aid in infection, though they doubtless serve other purposes as 
well. 

Perithecia of this species were first obtained by Clinton ^^^ who 
grew them in abundance on artificial media from sowings of coni- 
diospores taken from pure cultures. The typical Gloeosporium 
stage was also grown from ascospores. 

Perithecia were also found in pure cultures on apple agar by 
Spaulding and von Schrenk. They appeared in black knotted 
masses of mycelium which were often 4-5 mm. in diameter, the 
perithecia varying from one to many in each such stroma. The 
asci were evanescent, disappearing soon after the spores matured. 

That this fungus is the cause of a limb canker was suggested by 
Simpson's discovery of the canker in July, 1902 and was definitely 

proved by Spaulding 
and von Schrenck,-''^ 
and by Burrill and 
Blair ^^^ in the same 
year. 

In canker forma- 
tion the mycelium 
grows in the live 
bark, killing it and 
the cambium. The 
cankers are thought 
to be comparatively 
short lived, perhaps 
surviving only the 
third year. Reciprocal inoculations between fruit and twigs 
have proved the fungus in the two cases to be identical. Conidia 
and ascospores develop on both fruit and twigs. 

The fungus has been repeatedly grown in pure culture on numer- 
ous media by many investigators and many inoculations with 
conidia into both fruit and twigs have proved the causal relation 
of the fungus to the apple rot and twig canker. Inoculations from 
ascosporic material have given the same results. 

That the spores may be insect-borne was shown by Clinton; -''^ 
that they may also travel on the wind was shown by Burrill.-''^ 




Fig. 195. — G. rufomaculans, 
Note septa and appressoria. 
von Schrenk. 



germinating conidia. 
After Spaulding and 



THE FUNGI WHICH CAUSE PLANT DISEASE 



267 



The mycelium hibernates in hmb cankers and in mummified 
fruit.-^^ 

It is impossible morphologically to distinguish the conidial 
stages of many species of Gloeosporium and Colletotrichum grow- 
ing on a great variety of hosts, and much inoculation work has 
been done to ascertain the relationships existing between these 
many forms. Thus the author ^*^ in Dr. Halsted's laboratory 
made inoculations as indicated in Fig. 367. Southworth cross 
inoculated a Gloeosporium from 
grape to apple and from apple 
to grape; Stoneman from 
quince to apple. -^'' Even such 
cultures give little evidence of 
difference between these forms 
and it usually is impossible to 
distinguish between the conidial 
forms on either morphological 
or biological grounds. 

Some group under Glomeralla 
rufomaculans as its conidial 
forms, what were formerly 
known as Gloeosporium fructi- 
genum, G. rufomaculans, G. 
versicolor and G. Iseticolor. 

Further studies of the ascig- 
erous stages have led to con- 
solidation rather than to seg- 
regation of species. Thus an 
• ascigerous stage, a Glomer- 
ella, was obtained in pure 
culture from the following conidial forms by Shear and 
Wood: 258 

G. rufomaculans from grape, G. fructigenum from apple, G. 
sps. from cranberry, G. elasticse from Ficus (see p. 544) a Gloeo- 
sporium from Gleditschia, one from Ginkgo, Colletotrichum 
gossypii from cotton (see p. 271) and C. lindemuthianum. (See 
p. 547) from bean. These authors after careful study of these 
perithecia and cultures conclude that: "in the present state of 




Fig. 196. — Plate culture of G. rufomacu- 
lans showing perithecia-bearing 
masses. After Spaulding and von 
Schrenk. 



268 



THE FUNGI WHICH CAUSE PLANT DISEASE 



our knowledge, it may be best to regard the various forms we 
have studied as varieties of one species." 

Among the hosts of G. rufomaculans may probably be num- 
bered at least apple, grape, pear, quince, peach, tomato, egg- 
plant, pepper, sweet pea ~^^ and cherry.-''^ 
G. rufomaculans var. cyclaminis P. & C.^^^ 
Perithecia densely gregarious, indefinite, light-colored, around 

spots, brown, membranous, 
subglobose or distinctly ros- 
trate, ostiolate; asci clavate- 
cylindric, apex pointed, 50- 
65 X 8-9 /a; spores oblong 
to elliptic, 16-18 x 4-4.5 fx. 
C o n i d i a ( = Collet otri- 
chum) ; acervuli amphi- 
genous, brownish, large; 
conidia oblong to linear, 
obovate, straight, or shghtly 
curved, ends round, 12-15 x 
4-5 fi; conidiophores long, 
slender; setae free, short, 
rigid. 

This variety is reported 
on greenhouse Cyclamens, 
causing leaf spotting. Ma- 
ture perithecia were found 
on the leaves. Cultures 
from the ascospores gave a 
Colletotrichum as the co- 
nidial form and a similar Colletotrichum collected from the leaves 
in pure culture gave the Glomerella. 
G. cingulata (Atk.) S. & S. 

Perithecia cespitose, stromate, dark-brown, flask-shaped, mem- 
branous, 250-320 X 150 /jl, shortly rostrate, more or less hairy; 
asci clavate, 64-16 ^i; spores hyaline, elliptic, slightly curved, 
20-28 X 5-7 fji. 

Conidia ( = Gloeosporium cingulatum); acervuli 100-150 n, 
rupturing the epidermis, in age black; conidiophores numerous. 




Fig. 197. — (j. rufomaculans. Pustules on 
apple, enlarged. After Spaulding and von 
Schrenk. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



269 



crowded, simple, hyaline; conidia oblong to elliptic, straight or 
curved, basally pointed, 10-20 x 5-7 jjl. 

This was first described in conidial form as a Glceosporium by 
Atkinson -^° on privet as cause of cankers. The fungus was isolated 
and grown in pure culture. Later perithecia were obtained in 
the pure cultures.-''^ 

G. piperata (E. & E.) S. & S. 

Perithecia cespitose, thinly membranous, dark-brown, pyriform, 
hairy; asci clavate; spores slightly curved, elliptic, 12-18 x 4-6 ix. 




Fig. 198. — Diagrammatic section through acervulus of G. rufomaculans. 
a, parenchyma, h, cuticle, c, subhymenial fungous layer, d, conidiophores, 
e, spores, 6, conidiophores and conidia in detail. After Clinton. 

Conidia (= Glceosporium piperatum) on circular or oval spots; 
acervuli pustular, concentrically arranged, conidia 12-23 x 5-6 ix.-^^ 

The ascigerous stage was grown from pure cultures of the conidia 
taken from pepper by Miss Stoneman ^^^ the perithecia appearing 
about a month after inoculation. Typical conidia were also se- 
cured from ascospore sowings. 

G. cincta. (B. & C.) S. & S.--^ 

Perithecia 180-280 p., flask-shaped, membranous, cespitose; 
asci clavate, truncate or obtuse, 65-70 ii; spores elliptic, curved, 
5-20 x 3 11.-^^ 

Acervuli erumpent; conidia (=Colletotrichum cinctum) 12-15 x 



>-«SH^ 



270 



THE FUNGI WHICH CAUSE PLANT DISEASE 



3-4 IX, elliptic, guttulate; setiE present, but almost obscured by 
the spore mass. 

The ascigerous stage was demonstrated by Stoneman ^^'^ from 
pure culture studies. The conidial stage was described by Hal- 
sted -^^ as the cause of a blighting of orchid leaves (Sobralia) in 
New Jersey. 

Various hosts are orchids, Sarracenia, rubber plant, Dracaena "^ 
and Anthurium.^^^ 




Fig. 199. — G. rufomaculans, acerv'ulus showing conidia, 
conidiophores and setae. After Hasselbring. 

G. rubicola (Ston.) S. & S. 

Perithecia quite similar to those of G. piperata and G. cinta 
but lacking the apical tuft of hair and rather larger in size. 

Conidia ( = Colletotrichum rubicolum) forming large, dark- 
brown patches on the upper surface of the leaf; sori small, dark, 
suberumpent; conidia oblong, elliptic, 12.5 x 6 /z. 

The conidial form on red raspberry was shown by Stoneman ^^' 
by pure culture studies to possess this ascigerous stage. 

G. psidii (Del.) Shel.^*'''-26^ 

Perithecia 200-300 ix, spherical, rarely distinctly beaked; asci 



THE FUNGI WHICH CAUSE PLANT DISEASE 



271 



cylindric to broadly elavate, blunt, 45-55 x 9-10 /x; spores 
curved, continuous, granular, 13-15 x 5-6 n. 

Conidia (=Gloeosporium psidii), acervuli subepidermal on defi- 
nite spots, 90-120 ju; conidiophores hyaline, cylindric, 15-18 x 
4-5 fi; conidia elliptic, oval, hyaline, 10-13 x 4-6 n. 

Artificial culture studies by Sheldon ^^^' ^^"^ demonstrated the 
ascigerous stage. Extensive study was made of the growth on 




Fig. 200. — G. piperata, 99, perithecium external and in sec- 
tion. 100, asci in detail. After Stoneman. 



apple-agar, apples, plums, etc. Two distinct forms of conidia 
were observed, one on loose hyphse, the other in acervuli. The 
species should probably be regarded as a variety of G. rufo- 
maculans. 

It occurs on the guave. 

G. gossypii (South.) Edg. 

Perithecia distinct or crowded, very abundant, covered, dark 
brown to black, subglobose to pyriform, 80-120 x 100-160 n, 
beak up to 60 ^ long; asci numerous, elavate, 55-70 x 10-14 /x; 



272 



THE FUNGI WHICH CAUSE PLANT DISEASE 



spores elliptic, hyaline, rarely curved, 12-20 x 5-8 /x; paraphyses 
long and slender, very abundant. 

Conidia ( = Colletotrichum gossypii), acervuli erumpent, coni- 
diophores colorless, longer than the spores, 12-28 x 5 n; conidia 
irregularly oblong, hyaline or flesh-colored 
in mass; setae single or tufted, dark at base, 
colorless above, straight, rarely branched. 
The conidial stage of this fungus was de- 
scribed by Southworth ^^^' ^^^ and independ- 
ently by Atkinson -^"' ^^^' ^^ on cotton. 

The ascigerous stage was first seen by 
Shear & Wood -^^ in artificial culture and by 
them regarded as probably a variety of G. 
rufomaculans. Since these studies Edger- 
ton -^^ from examination of perithecia de- 
veloped naturally in the open, has proposed 
it as a separate species. 

The mycelium is richly branched and sep- 
tate, usually hyaline but sometimes slightly 
Fig 201.— G. gossypii. ^moky. It grows between and in the host 
Section of young "boll, cells which are often filled with it, causing 

showing the fungus r i i in 11 

penetrating the hull collapse, loss 01 chlorophyll, and brownmg. 
young "^seed/ "^ Spores Studies by Atkinson and by Barre ^^^ show 
are being produced ^hat in case of diseased bolls the mycelium 

upon the outer por- ^ "^ 

tion of the hull and may extend through the pericarp, sporing on 

upon the surface of ., . ,, , i ,1 , ,1 i 

the young seed coat, its inner Wall; extend thence to the seeds; 

After Barre. penetrate and grow in them, Fig. 201, and in 

the cells of the lint. Barre has shown that even the endosperm 
and cotyledons may be invaded, Fig. 201, and spores produced 
upon them while within the seed coats. Such seeds and lint may 
appear outwardly as though perfectly normal. 

The conidia are formed in acervuli, subtended by stromata. 
Setae, from few to many increasing with age of the acervulus, 
are present and conidia are occasionally found on them. In ger- 
mination conidia usually develop one, sometimes two septa and 
produce dark chlamydospores. Acervuli are common on bolls, 
less so and smaller on leaves and stems. 

The perithecia as found in the field by Edgerton in Louisiana 




THE FUNGI WHICH CAUSE PLANT DISEASE 



273 




were usually entirely embedded, with the beaks only protruding 
and were often numerous and crowded. Cultural evidence that 
Edgerton's specimens were actually genetically connected with 
the cotton anthracnose are wanting. 

The fungus has been repeatedly studied in pure culture and 
numerous inoculations have thoroughly proved its pathogenicity, 
the disease usually showing within 
a few days after inoculation, though 
sometimes incubation is delayed 
much longer. 

Infection of stems is often at a 
wound such as a leaf scar; or on 
leaves at some point of weakness. 
Cotyledons and young plants are 
especially susceptible. On bolls 
infection is common at the line 
of dehiscence of the carpels. Ac- 
cording to Barre, tRere is evidence 
that the fungus may destroy the contents of the boll before 
it shows upon the outside. Barre showed that 44% of flowers 
that received spores within ten hours after opening produced dis- 
eased bolls; but inoculations by spraying produced no results on 
bolls after they were three-fourths grown. 

Seed from a field that bore 35% infected bolls gave on germina- 
tion, 12% of infected seedlings, the disease appearing upon cotyle- 
dons or hypocotyls even before they unfolded. Atkinson ^"° found 
that conidia five months old were alive, but that at seven months 
they failed to germinate. Barre also found the conidia and the 
mycelium of the fungus to be comparatively short lived. 

G. atrocarpi Del. on Atrocarpus leaves has been described as 
a perfect stage of Gloeosporium atrocarpi Del. 

A fungus on Cattleya ^''^' -^- described by Maublanc & Lasnier 
as a Physalospora should perhaps be considered as a Glomerella. 



Fig. 202. — G. gossypii, D, and E, fun- 
gus gro-.v-ing in cotton lint fibers. 
After Barre. 



Gnomoniella Saccardo (p. 263) 

Perithecia sunken and usually remaining so, with a long cylin- 
dric, erumpent ostiole, leathery, black; asci ellipsoid or fusoid. 



274 



THE FUNGI WHICH CAUSE PLANT DISEASE 




apically thickened and opening by a pore; 
spore elliptic, 1-celled, hyaline; paraphyses 
none. 

This genus of some twenty-five species 
contains G. tubiformis (Tode) Sacc. which 
Fig. 203.— g. tubifor- jg g^^j^^ ^q j^g ^j^g ascigerous stage of Lepto- 

mis, pentnecia. After ° , ° ^ 

thyrium alneum Sacc. growing on Alder. 
G. fimbriata and G. coryli are found on 



Winter 

Two other species, 



hornbeam and hazel respectively. 

Gnomonia Cesati & de Notaris (p. 264) 

Perithecia covered, or erumpent, submembranous, glabrous, 
ostiole more or less elongate; asci ellipsoid or fusoid, apically thick- 
ened, opening by a pore; spores elongate, hyaline, 2 to 4-celled; 
paraphyses none. 

There are some sixty species. Fusicoccum, Myxosporium, Sporo- 
nema, Gloeosporium, Marssonia, Asteroma, Leptothyrium occur in 
some species as the conidial form. The ascigerous form usually 
follows as a saprophyte after the parasitic conidial stage. 

G. veneta (Sacc. & Speg.) Kleb.^^^. 222. 323. 335 

Perithecia immersed, subglobose or slightly flattened, 150- 
200 n, short, rostrate; asci long-clavate, 48-60 x 12-15 n, gen- 
erally bent at right angles at the base, apically very thick, opening 
by a pore; spores 14-19 x 4-5, straight 
or slightly curved, unequally 2-celled, 
the upper cell longer. 

Conidia variable in habitat, and 
habit. (1) ( = Gloeosporium nervise- 
quum) acervuli subcuticular 100- 
300 ix; conidiophores short, conidia 
oozing out in a creamy-white mass, 
hyaline, elhpsoid, 10-14 x 4-6 ix, 
pointed at one end and rounded at the 
other. (2) ( =G. platani) acervuU sub- 
epidermal, conidiophores long; conidia 
as above. (3) ( =Discula platani = Myxosporium valsoideum) form- 
ing minute, subepidermal, erumpent pustules on twigs; conidia 
elliptic to oblong, hyaline, 8-14 x 4-6 ju; (4) ( =Sporonema platani 




■G. veneta, perithe- 
After Edgerton. 




THE FUNGI WHICH CAUSE PLANT DISEASE 275 

= Fuscicoccum veroncnse). Pycnidia formed on old leaves on 
the ground, crumpent, subcuticular, brown, 200-300 jn; conidia 
numerous, oblong, ovoid to fusoid, 7-11 x 3-4 /j,. 

The conidial form on sycamore and oak, first described in 1848, 
is common on leaves and young branches, the mycelium checking 
the sap-flow and causing death of surround- 
ing tissue. A stroma is formed on the outer 
layers of the mesophyll and from this arise 
the short conidiophores to constitute the 
acervulus. 

Infection experiments by Tavel ~'^^ gave 
negative results. Other infection experiments 
have also been unsatisfactory. 

The ascigerous form was first found by 
Klebahn274 on old leaves on which it ma- -^'anf sp^r?s.'^ a£ Ed- 
tured about Christmas time. While the co- gertou. 
nidia are uniform in shape four modes of development are found, 
as stated above. 

Pure cultures from all the spore forms were compared by Edger- 
ton ^-- confirming Klcbahn's conclusion as to their identity. Cul- 
tures by Stoneman ^^^ showed the forms on sycamore and oak to 
be the same. 

G. leptostyla (Fr.) Ces. & d. Not. 

Perithecia conic, short-beaked; asci subclavate, 45-65 x 10-12 
jj,; spores fusoid, curved, 18-22 x 4 /i, hyaline. Conidial phase 
(=Marssonia juglandis). Acervuli gregarious, hypophyllous, 
rounded; conidia obovoid, 8-10 x 4-5 n, 1-septate, pointed 
above, truncate below, greenish. 

The connection between the conidial and ascigerous forms was 
demonstrated by Klebahn -^" by pure cultures and by ascosporic 
infection. The conidial form is common on walnut leaves; espe- 
cially severe on the butter-nut (Juglans cinerea) often defoliating 
this host in mid-summer. 

G. quercus-ilicis Berl. occurs on oak leaves in Italy. 

G. erythrostoma Auer. is the cause of a disease of cherry leaves 
in Europe; ^''^' ^^^ 

G. padicola Kleb. is the ascigerous stage of Asteroma padi 
which is widely distributed in Europe on Prunus. 



276 THE FUNGI WHICH CAUSE PLANT DISEASE 

G. oryzae Miy. occurs on rice.-"^ 

G. rubi Rehm may occasionally cause disease of blackberry 
canes. "^^ 

Rehmiellopsis Bubak & Kabat (p. 264) 

Similar to Rehmiella except that the perithecia are not beaked 
and the pycnidia do not have a definite opening. 

R. bohemica Bub. & Kab.; (conidia=Phoma bohemica)^^^ oc- 
curs as a parasite on fir needles. 

Clypeosphaeriaceae (p. 223) 

Perithecia immersed, astromatic or with a pseudostroma built 
of hyphse which, with the adjacent substratum, forms a thin cly- 
peus that is usually evident only above; ostiole short to long- 
beaked, erumpent, walls mostly carbonous to membranous; 
paraphyses usually present. 

A small family chiefly saprophytes. 

Key to Genera of Clypeosphaeriaceae 

Spores 1 -celled 
Perithecia soft-membranous, spores hya- 
line or brown 1. Trabutia. 

Perithecia leathery; spores brown 2. Anthostomella, p. 276. 

Spores more than one-celled 
Spores with cross walls only 

Spores cylindric, ellipsoid or fusiform 

Spores hyaline, 1 to 3-septate 3. Hypospila. 

Spores brown 

Spores elongate 4. Clypeosphaeria. 

Spores fusiform, more than 4- 

septate, sometimes muriform . 5. Phaeopeltosphaeria. 

Spores filiform, hyaline to yellow 6. Linospora. 

Spores muriform 

Spores ovate, brown 7. Peltosphaeria. 

Spores short, fusiform, hyaline 8. Isothea. 

Anthostomella Saccardo 

Mycelium fusing with the upper surface of the substratum to 
form a thin, black, rounded pseudostroma; perithecia sunken, sub- 



THE FUNGI WHICH CAUSE PLANT DISEASE 



277 



globose, with a short, conical ostiole, walls 
black, carbonous to leathery; asci cylindric, 
8-spored; spores elliptic, continuous, brown, 
unappendaged ; paraphyses usually present. 

Over one hundred species, chiefly sapro- 
phytes. 

A. sullas Montem, occurs as the cause of a 
leaf spot on sulla.-^^ Fig. 206.— a. des- 

A. bohiensis (Hmp.) Speg. is on cacao; ^eiumT'^, t^us'w', 

A. destruens Sh. on cranberry; spores; n, germi- 

■^ ' Dating spore. After 




A. coffeae Desm, on coffee. ^^^' ~^^ 



Shear. 



Valsaceae (p. 223) 

Stroma effused, subglobose, conic, or pulvinate, often indefinite; 
perithecia sunken in the stroma, scattered or clustered, black, 
leathery; asci cylindric or clavate; paraphyses usually present. 

Over one thousand species, chiefly saprophytic. Conidia are 
present on hypha; or in pycnidia. 

Key to Genera of Valsaceae 
Spores 1-celled 

Spores cylindric or ellipsoid, with a brown 

membrane 1. Anthostoma. 

Spores ellipsoid, curved or not, with a 

hyaline membrane. . . .• 2. Valsa, p. 278. 

Spores more than I-celled 
Spores with cross walls only 
Spores hyaline 

Spores unappendaged 

Spores ellipsoid or fusoid 2 to 4- 

celled 3. Diaporthe, p. 278. 

Spores elongate, fusoid, constricted 

in the middle 4. Vialaea. 

Spores appendagcd, 1 appendage at 
each end and 2 or 3 in the mid- 
dle 5. Caudospora. 

Spores brown 

Spores 2-celled, ellipsoid 6. Rhynchostoma. 

Spores many-celled, fusoid 7. Kalmusia. 



278 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Spores muriform 
Stroma effused 

Spores hyaline 8. Thyridella. 

Spores colored 9. Thyridium. 

Stroma none or pulvinate 10. Fenestella. 

Valsa Fries (p. 277) 

Perithecia on a more or less definite stroma, immersed, the 
ostiole enimpent, black, firm; asci globose to cylijidrie, often 

long-pedunculate ; spores 

^^^ -r-^^f^^^^^^, ^e'^^^qh 1-celled, rarely 2-celled, 

lr\^? ^*4l)l r^&te M^'3 cylindric, rounded, hya- 

r * « t. ,y*rfW \/a^3*^ \'j Wrap'- V r i- i,j. u 

k *^»**v .IP|^^ mjf \^)J^^l ^io^ ^1^6 or light-brown; pa- 

mf 1^*^, J iVs^JC^"' €"? li^ r- '/ c^ raphyses none. 

^l*S"s .lUI^C^^J B V. leucostoma (Pers.) 

^^"^r^^I!!!r^"^"^=^ 22, 229, 280 

Fig. 207.— Valsa. A, habit sketch; B, perithecia; Stroma strongly COn- 
C.asci. After Tulasne. ^^^^ 2-3 mm., whitish 

and granular within, outer layer coriaceous; perithecia immersed; 
asci fusoid-clavate, subsessile, 35-45 x 7-8 m; spores biseriate, 
allantoid, hyaline, slightly curved, 9-12 x 2-2.5 /x. 

Conidia ( = Cytospora rubescens); stromate, erumpent, reddish; 
conidia allantoid, 4 fx. On pome and stone fruits throughout 
Europe, Australia and America causing the disease known as 
" dieback." The fungus was studied by Rolfs "^^' ^^^ who worked 
out its life cycle. 

V. oxystoma Rehm. occurs on Alnus in Europe; 

V. (Eutypa) caulivora Rehm. affects Hevea. 

V. ambiens Fr. is on the apple in Europe. 

V. (Eutypella) prunastri (Pers.) Fr. is the cause of serious dis- 
eases of apples, plums, etc., in England. 

V. (Eutypa) erumpens Mas. is reported as a wound parasite 
in the tropics on Ficus, and cacao. 

Diaporthe Nitschke (p. 277) 

Stroma very variable, usually definite; perithecia membranous 
subcoriaceous, generally pale-cinereous within, with a cylindric 
or filiform beak; asci fusoid; spores fusoid to subelliptic, 2-celled, 



THE FUNGI WHICH CAUSE PLANT DISEASE 



279 



hyaline, appendaged or not; pa- 
raphyses none. Conidia=Phoma, 
Cytospora, etc. 

D. taleola (Fr.) Sacc. 

Stroma cortical, definite, de- 
pressed, pulvinate, 2-4 mm., cov- 
ered; perithecia few, 4-10, buried, 
their ostioles converging, erumpent 
in a small light-colored disk; asci 
cylindric, 120-140 x 10-12 ix, spores 
elliptic, uniseptate, constricted, with 
setaceous appendages, 15-22 x 
8-9 II. 

It causes canker on oak, killing 
the cortex over large areas. A 
year later the cushion-like stromata 
appear. The mycelium penetrates 
both wood and bark, probably enter- 
ing through wounds. 

D. albocarnis E. & E. on Cornus is destructive. 

D. ambigua and D. sarmentella are on pear and hop, D. stru- 
mella on a wide range of hosts, in conidial form as Phoma. 




Fig. 208. — Diaporthe. 
in section; C, asci. 
lasne. 



o 

B, stroma, 
After Tu- 



Melanconidaceae (p. 223) 

A small family of less than two hundred species contains only 
four parasitic genera. 

Stroma pulvinate, sunken; perithecia sunken in the stroma, 
the mouth erumpent; asci cylindric or clavate; paraphyses present. 

Key to the Genera of Melanconidaceae 

Spores 1-celled, hyaline 

Spores ellipsoid or short-fusiform 1. Cryptosporella, p. 280. 

Spores elongate-cylindric, curved 2. Cryptospora. 

Spores 2-celled 
Spores hyaline 

Conidiainpycnidia; 1-celIed, hyaline. . 3. Valsaria. 
Conidia not in pycnidia, dark brown. . 4. Melanconis, p. 281. 
Spores brown 5. Melanconiella. 



'N. 



280 THE FUNGI WHICH CAUSE PLANT DISEASE 

Spores more than 2-celled 
Spores hyaline 

Spores elongate, multicellular 6. Calospora, p. 280. 

Spores fusiform, multicellular 7. Holstiella. 

Spores brown 

Spores elongate, multicellular; asci 

8 or 4-spored 8. Pseudovalsa, p. 281. 

Spores long-cylindric, very large, asci 

1-spored 9. Titania. 

Calospora Saccardo 

One species, C. vanillae Mas., reported as causing a Vanilla 
trouble,'^^^ is perhaps identical with Gloeosporium vanillae C. & M. 



^>^vi,w^j^'^ 



Cryptosporella Tulasne (p. 279) 

Stroma valsoid, pustuHform, covered; perithecia embedded, 
subcircinate, with converging necks united in an erumpent disk; 

asci cylindric to globoid; spores 
elongate, cylindric, hyaline, 1-celled. 
C. anomala (Pk.) Sacc.-^«' -^' 
Pustules prominent, 2-5 mm., 
erumpent; penetrating the wood 
and generally having a thin black 
crust beneath them, disk convex or 
slightly depressed, cinereous to black ; 
perithecia crowded, deeply em- 
bedded in the stroma, often elon- 
gate, ostioles scattered, black; asci 
short, broad, fugaceous; spores hya- 
line, elliptic, simple, 7-8 /x. 

Common on hazel and filbert in 
America, causing the destruction of the tops while the roots re- 
main alive. 

C. viticola Sh.^^^ 

Pycnidia (=Fusicoccum) with labyrinthiform chambers, ostiolate 
but frequently rupturing. Spores hyaline, continuous, of two forms 
in the same cavity. 1. Subfusoid, 7.5 x 2-5 ju- 2. Long, slender, 
curved, 18-30 x 1-1.5 /i. Perithecia buried in irregular pulvinate 




Fig. 209. — C. anomala. 31, stroma 
and perithecia; 32, an ascus; 33, 
spores. After Humphrey. 



THE FUNGI WHICH CAUSE PLANT DISEASE 281 

stromata, beak exserted; asci 60-72 x 7-8 ^l^, paraphyses slender, 
septate, wavy; ascospores subelliptic, hyaline, continuous, 11-15 x 
4-6 /x. Fig. 210. 

The conidial stage was described by Reddick as the cause of 
necrosis of grape vines ^^^ though he has since stated that the 
amount of damage due to this disease is not so great as at first 
thought. 

The ascigerous form in pure culture in the hands of Shear ^-'^ 
gave rise to the typical conidial form, identical with that grown 
from pure cultures of the pycnospores. 

Melanconis Tulasne (p. 279) 

Stroma valsoid, seated in the substratum, partially erumpent; 
perithecia clavate, immersed, with long cylindric beak; asci cylin- 
dric, long-clavate, 8-spored; spores ellipsoid to elongate, hyaline. 

About twenty species; chiefly saprophytes. 

M. modonia Tul. in its conidial form (=Fusicoccum pernicio- 
sum) causes a serious disease of the chestnut in Europe,^^^' ^^^ 

Pseudovalsa longipes (Tul.) Sacc. is parasitic on oak. 

Diatrypaceae (p. 223) 

Stroma effused or pulvinate, built of thick hyphse, under the 
peridium, at length erumpent, bearing both asci and conidia or 
present only with the conidia; perithecia sunken in the stroma or 
superficial, ostiolate; asci usually thickened apically; 4 to 8 or 
many-spored; spores usually continuous, small, cylindric, curved. 

About one hundred seventy-five species. 

One parasitic genus occurs on cherry and plum. 

Key to Tribes and Genera of Diatrypaceae 

Stroma absent from ascosporic stage I. Calosphaerieae. 

Asci 8 (rarely 4)-spored 

Spores l-celled 1. Calosphaeria, p. 282. 

Spores 2-celled 2. Cacosphaeria. 

Asci many-spored 3. Coronophora. 

Stroma present in the ascosporic stage II. Diatrypeae. 



282 



THE P^UNGI WHICH CAUSE PLANT DISEASE 



Calosphaeria. Tulasne (p. 281) 

Perithecia astromate, free or on the inner bark, scattered or 
clustered, ostiole more or less elongate; asci clavate, fasciculate; 
spores small, cylindric, curved, hyaline, continuous; paraphyses 
longer than the asci, stout lanceolate, evanescent. 

About thirty-five species chiefly saprophytes. 

C. princeps Tul. 

Perithecia on the inner bark in orbicular or elliptic groups, gen- 
erally densely crowded, globose, smooth and shining, necks long, 




Fig. 210.— Crypto- 
sporella viticola. 
Asci and pa- 
raphyses. After 
Shear. 




1.0' 



Fig. 211. — Calosphajria princeps. A, group of 
perithecia; B, conidial stroma. After Tu- 
lasne. 



decumbent, flexuose, cylindric, erumpent; asci 12-26 x 4 /z, 
spores 5-6 x 1-5 ^i. 

On plum, cherry, peach and even pomaceous trees. 



Melogrammataceae (p. 223) 

Stroma usually pulvinate, rarely effused, hemispheric, sub- 
peridial then erumpent and more or less superficial; perithecia 
sunken in the stroma; conidia occur in acervuli on the surface of 
the young stromata, or in pycnidia. 

A small family of about one hundred twenty-five species, only 
one genus of which contains important pathogens. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



283 



Key to Genera of Melogrammataceae 

Spores l-celled 

Spores roundish ellipsoid, asci long fusi- 
form 1. Gibelia. 

Spores ellipsoid or ovate, asci clavate. ... 2. Botryosphaeria, p. 283. 
Spores 2 or more-celled 

Spores with cross walls only 
Spores 2-celled 
Spores hyaline 

Paraphyses present 3. Endothia. 

Paraphyses absent 4. Myrmaeciella. 

Spores brown 5. Myrmaecium. 

Spores more than 2-celled, ellipsoid to 
filiform 

Spores hyaline many-celled 6. Sillia. 

Spores hyaline 3-celled 7. Melanops, p. 284. 

Spores brown 8. Melogramma, p. 284. 

Spores muriform 9. Berlesiella. 



Botryosphaeria Cesati & de Notaris 

Stroma pulvinate, black; perithecia at first sunken in the stroma, 
remaining so or becoming 
more or less prominent, 
usually small, globose, os- 
tiole inconspicuous, papilli- 
form; asci clavate; spores 
elliptic to oval, hyaline, 
continuous; paraphyses 
present. 

B. ribis G. &. Dug.-^s 

Stromata black, more or 
less pulvinate, outer sur- 
face botryose, 1-4 mm. in 
diameter, usually 2-3 mm., 
and surrounded by the 
fissured periderm, regularly scattered or in more or less definite, 
longitudinal rows or elongated stromata. Perithecia somewhat 




Fig. 212. — Botryosphferia. B, stroma 

tion; C, part of perithecium and pycnidium 
in section. After Tulasne. 



sec- 



284 THE FUNGI WHICH CAUSE PLANT DISEASE 

top-shaped, with papillate ostioles and usually projecting, some- 
times practically superficial. Few to many in a stroma and usually 
interspersed among pycnidia; 175-250 n in width. Asci clavate, 
80-120 X 17-20 fx, and with numerous filiform paraphyses. 
Spores fusoid, continuous, hyaline, 16-23 x 5-7 /x. 

Pycnidia of the compound stylospbric form, Dothiorella, are borne 
m the same or similar stromata; spores fusoid, continuous, hyaline, 
18-31 X 4.5-8 ix. Pycnidia of the simple stylosporic form, Macro- 
phoma, are embedded in the outer bark under the much-raised 
primary cortex of young shoots, depressed globular, 175-250 mm. 
wide; spores fusoid, hyaline, continuous, 16-25 x 4.5-7.5 ju. 

The cause of a blight of canes of currants. 

The fungus was first noted in sterile form by Fairchild."^^ Its 
history was first fully worked out by Grossenbacher & Duggar.-^^ 
Extensive inoculation experiments and pure culture studies de- 
finitely established its pathogenicity. 

B. dothidae Ces. & d. Not. causes epidemics of disease among 
cultivated roses. 

B. gregaria Sacc. is injurious on willows in Europe.^^^ 

Melanops Fuckel (p. 283) 

Stroma lens-shaped, black; perithecia sunken; asci elongate, 
8-spored; spores elongate, 3-celled, hyaline; paraphyses elongate, 
brown. 

According to Shear, ^^^ the conidial stage of some members of 
this genus is a Sphseropsis which is indistinguishable from S. vitic- 
ola and S. malorum. 

Melogramma henriquetii Br. & Cav. is parasitic on cork oak. 

Xylariaceae (p. 224) 

Stroma variable, usually free but often more or less sunken in 
the matrix, either upright and often branched or horizontal, ef- 
fused, crustaceous, pulvinate, globose or hemispheric, black or 
becoming black, usually woody or carbonous; perithecia periph- 
eral, immersed, leathery or carbonous, black; asci cylindric or 
cylindric-clavate, 8-spored; spores continuous, brown or black, 
fusiform or ellipsoid, paraphyses present or absent. 

A family of over five hundred species. 



THE FUNGI WHICH CAUSE PLANT DISEASE 285 



Key to Genera of Xylariaceae 

Stroma encrusted, shield-form, globose or 

hemispheric, without a sterile base. ... I. Hypoxyleae. 
Conidial laj'er beneath the surface of the 

stroma, erumpent 1. Nummularia, p. 285. 

Conidial layer free from the first 
Stroma encrusted 

Spores 1-celled 2. Bolinia. 

Spores 2-celled 3. Camarops. 

Stroma discoid to hemispheric, en- 
crusted together 
Young stroma fleshy, covered by 

conidia, at length carbonous. . . 4. Ustulina, p. 286. 
Stroma carbonous or woody from the 
first 
Stroma without concentric layers. 5. Hypoxylon. 
Stroma with concentric layers ... . 6. Daldinia. 
Stroma erect, simple or branched, clavate or 

cylindric, with a sterile base II. Xylarieae. 

Most of these genera are saprophytic on wood or bark. 



Nummularia Tulasne 

Stroma orbicular, cupulate or discoid, becoming black, mar- 
ginate; perithecia monostichous, peripheral, immersed; asci cy- 
lindric; spores subelliptic, continuous, dark. 

The genus contains forty species. Only one is recorded as 
injurious. 

N. discreta (Schw.) Tul. 

Stroma erumpent, orbicular, 2-4 mm., cupulate, with a thick 
raised margin; ovate, cylindric, nearly 1 mm. long, abruptly con- 
tracted above into a short neck; asci 110-120 x 10-12 /x] spores 
subglobose, nearly hyaline, then opaque, 10-12 /x; paraphyses 
filiform. 

This fungus is usually a saprophyte but has been reported by 
Hasselbring as a serious parasite on the apple in Illinois. -^^ 

The mycelium grows more rapidly in the wood than in the bark, 



286 



THE FUNGI WHICH CAUSE PLANT DISEASE 



attacking first the parenchyma cells and medullary rays. The 
young stromata appear under the bark bearing when young small 
unicellular conidia. The stromata later turn hard and black and 







D 



Figs. 213-214. — N. discreta, B, stroma and perithecia, C, a 
perithecium, D. asci and spores. After Hasselbring. 

in the upper layers bear numerous flask-shaped perithecia with 
long necks, Figs. 213-214. 



Ustulina Tulasne (p. 285) 

Stroma superficial, subeffuse, rather thick, determinate, at first 
clothed with a pulverulent cinereous conidial hymenium, finally 
rigid, carbonous, black, bare and generally more or less hollow; 



THE FUNGI WHICH CAUSE PLANT DISEASE 287 

perithecia immersed, large, papillate-ostiolate; asci pedicellate, 
8-spored; spores ovoid-fusiform; paraphyses present. 

A genus of about ten species, chiefly saprophytes. 

U. zonata Lev. is the cause of the commonest root disease of 
tea and is common also on Hevea. 



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288 



BIBLIOGRAPHY OF A8C0MYCETES 289 

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290 THE P^UNGI WHICH CAUSE PLANT DISEASE 

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88 Arthur, J. C, N. Y. (Geneva) R. 5: 291, 1886. 

89 Humphrey, J. E., Mass. State R. 10: 239, 1892. 

90 Salmon, E., Zeit. 11: 76, 1901. 

91 Salmon, E., Tr. Ag. Sc. 2: 327, 1907. 

92 Bailey, L. H., N. Y. (Cornell) B. 74: 381, 1894. 

93 Halsted, B. D., N. J. R. 13: 281, 1892. 

94 Halsted, B. D., U. S. D. Ag. R. 376, 1887. 

95 Mass. R. 10: 240, 1892. 

99 Mass. R. 10: 252, (1892), 1893. 

97 Halsted, B. D., N. J. R. U: 357, 1893. 

98 Salmon, E., New Phytologist, 3: 109, 1904. 

99 Reed, G. M., Univ. of Wis. B. 250, 1908. 

100 Wolff, Beitr. zur Kennt d. Schm.— pilze. 1875. 

101 Marchal, C. R. 135: 210, 1902. 

102 Salmon, Beih. Bot. Cent. 1^: 261, 1903. 

103 U. S. D. Ag. R. 105, 1886. 

10" Galloway, B. T., Bot. Gaz. 20: 486, 1895. 

105 Bioletti, Cal. B. 186: 1907. 

106 Riv. d. vit. 655: 9. 

107 Couderc, G., C. R. 116: 210, 1893. 

108 Pammel, L. H., Iowa, B. 13: 921, 1891. 

109 U. S. Dept. Agric. R. 352, 1888. 

110 Salmon, E. S., Mon. Torr. CI. 9: 36, 1910. 

111 Vanha, J., Zeit. U: 178, 1904. 



BIBLIOGRAPHY OF ASCOMYCETES 291 

12 Eriksson, J., Bot. Cent. 26: 335, 1886. 

" Fawcett, H. S., Fla. R. 40: 1909. 

1^ Palla, Ber. d. deut. Bot. Ges. 17: 64, 1899. 

15 Fallow, W. G., Bull. Buss. Inst., 40-1, 1876. 

16 Swingle, W. T. & Webber, H. J., V. P. P. B. 8: 25, 896. 
" Webber, H. J., V. P. P. B. 13: 1897. 
'« Fawcett, H. S. & Rolfs P. H., Fla. B. 94. 
19 Fawcett, H. S., Univ. of Fla. Spec. Studies 1: 1908. 
2« Seaver, F. J., Mycologia 1: 41, 1909, 177. 
21 Aderhold & Ruhland, Arb. a. d. Biol. Abt. f. Land. u. Forst am Kais. 

Gesund. 4: 429, 1905. 

'2 Idem, 2: 48, 1909-1910. 

23 Berlese, A. N., Riv. d. Pat. Veg. 5: 88, 1897. 

2" Boeuf, F., B. d. Dir. d. L'Ag. et d. Comm. Tunis, 27: 1903, also 1905. 

» Paddock, W., N. Y. (Geneva) B. 163: 204, 1899. 

^» Durand, E. J., N. Y. (Cornell) B. 125: 1897. 

" Grossenbacher, J. G., & Duggar, B. M., N. Y. (Geneva) T. B. 18: 
1911. 

28 Mayer, H., Unt. forst bot. Inst. Munchen 3: 1, 1883. 

29 Halsted, B. D., N. J. R. 12: 281, 1891; and 359, 1894. 

30 Massee, Kew Bui. Jan. and Feb., 1899. 

31 Ihssen, G., C. Bak. 27: 48, May, 1910. 

32 Smith, E. F., B. V. P. P. 17: 1899. 

33 Higgins, B. B., Sc. 31: 916, 1910. 
31 Higgins, B. B., N. C. R. 32: 100, 1910. 
35 Butler, Mem. Dept. Agric. India, Bot. Ser. 2: 9, 1910. 
3« Zimmermann, A., C. Bak. 8: 148. 

37 Fetch, T., Circ. & Ag. Jour. Roy. Bot. Gard. Ceylon, Nov., 1910. 

38 Selby, A. D. and Manns, T. F., Ohio B. 203. 

39 Selby, A. D., Ohio B. 97: 40, 1898. 
«Sorakin, N., Zeit. 1: 238, 1891. 

11 Cavara, Zeit. 3: 16, 1893. 

12 Noack, F., Zeit. 10: 327, 1900. 

13 Fetch, T., Circ. & Ag. J. Roy. Bot. Gard. Ceylon, 8: 65, 1910. 
11 Frank, Ber. deut. Bot. Ges. 1: 58, 1883. 

5 Atkinson, G. F., J. Myc. 11: 248, 1905. 

8 Miyake, Bot. Mag. Tokyo Ag. 1908. 

7 Williams, T. A., S. D. B. 33: 38. 
« Stager, R., Bot. Zeit. Ill, 1903. 

19 Stevens, F. L., & Hall, J. G., Bot. Gaz. 50: 460, 1910. 
5« Brefeld, 0., Untersuch. 12: 194. 



292 THE FUNGI WHICH CAUSE PLANT DISEASE 

" Fulton, H. R., La. B. 105: 17, 1908. 
" Patterson, F., and Charles, V. K., B. P. I. 171: 9, 1910. 
" Lodeman, E. G., N. Y. (Cornell) B. 81: 1894. 
5^ Farlow, W. G., Bui. Bussey Inst., 440, 1876. 
" Beach, S. A., N. Y. (Geneva) B. 40: 25, 1894. 
5« Humphrey, J. E., Mass. R. 8: 200, 1891. 
" Garman, H., Ky. B. 80: 250, 1899. 
*^ Schweinitz, Syn. Fung. Carol. Sap. 134. 
59 Ruhland, W., C. Bak. 12: 250, 1904. 
8« Cooke, M. C, Grevillea 13: 63. 
" Clevenger, I. T., Jour. Myc. 11: 160, 1905. 

«2 Hohnel, F. von, Sitz, K. Akad. Wis. Vienna Math. Nat. Kl. 118: 
813. 

" Shear, C. L., B. P. I. B. 110 and Torr. Bui. 84: 305. 

" Wakker & Went. De Sietleen von het suikerriet op Java, 153: 1898. 

«5 Massee, Ann. Bot. 7: 515, 1893. 

66 Massee, Ann. Bot. 10: 583, 1896. 

^' Hartig, Hedw. 12: 1888; Allegm. Forst. u. Jagd,— Zeit. Jan. 1884. 

"8 Tubeuf, Bot. Cent. 41: 1890. 

89 Hartig, Hedw. 12: 1888. 

■0 Stewart, F. C. & Blodgett, F. H., N. Y. (Geneva) B. 167: 1899. 

^1 Pierce, N. B., V. P. P. B. 154: 1892. 

^2 Viala, Pourridie d. Vignes et d. Arbres fruitiers. 

" Prillieux, C. R. 135: 275, 1902. 

7^ Behrens, J., C. Bak. 3: 584, 1897. 

" Whitson, E. P., Sandsten et al, Wis. R. 21: 237. 

^6 Schrenk, H. von, B. P. L B. 36: 1903. 

" Hedgcock, R. Mo. Bot. Card. 17: 59, 1906. 

^« Heald, F. D. & Wolf, F. A., Mycologia 2: 205, 1910. 

'9 Tubeuf, C. von, Zeit. 3: 142, 1893. 

«o Vuillemin, Jour, de Bot. 1: 315, 1888; 2: 255, 1890. 

". Smith, R. E., Cal. B. 191: 1907. 

«2 Viala & Ravaz, Prog. Agr. Et. Vit. 9: 490, 188. 

«3 Viala & Ravaz, B. Soc. Myc. d. Fr. 8: 63, 1892. 

«" Jaczewski, A. von, Zeit. 10: 257, 1900. 

85 Scribner, F. L., U. S. Dept. Agric. R. 109, 1886. 

«6 Rathay, E., Zeit. 306, 1891. 

" Chester, F. D., Del. B. 6: 1889. 

8« Shear, C. L., Miles, G. F., Hawkins, L. A., B. P. L B. 155: 1909. 

89 Price, R. H., Texas B. 23: 1892. 

9" Reddick, D., N. Y. (Cornell) B. 293: 1911. 



BIBLIOGRAPHY OF ASCOMYCETES 293 

>" Prillieux, B., Soc. M. d. Fr. 4: 59, 1888. 
''^ Shear, C. L., B. P. I. B. 110: 15, 1907. 
133 Prillieux & Delacroix, C. R. 130: 298, 1900. 
"^ Shear, C. L., Bui. Torr. Bot. Club, 3^: 305, 1907. 
"'^ Shear, C. L., Bui. B. P. I. B. 110. 
"8 Bernard, Ch., Bui. Depot Agric. Ind. Neerland 6: 1907. 
1" Seribner, U. S. Dept. Agr. R. 334, 1887. 
"« Dudley, W. R., N. Y. (Cornell) B. U: 1889. 
i^^Pammel, L. H., la. B. 13: 70, 1891. 

2™ Stewart, F. C. & Eustace, H. J., N. Y. (Geneva) B. 226: 356, 
1902. 

201 Aderhold, Ber. d. deut. Bot. Ges. 18: 242, 1900. 

202 Klebahn, H., Zeit. 18: 5, 1908. 

203 Duggar, B. M., N. Y. (Cornell) B. U5: 1898. 
20" Atkinson, G. F., Garden & Forest 10: 73, 1897. 

205 Grossenbacher, J. G., N. Y. (Geneva), T. B. 9: 1909. 

206 Jour. Bd. Agr. London, 17: 215. 

20- Zeit. 3: 90; 4: 13, Frank, C. Bak. 5: 197, 1899. 

208 Halsted, B. D., N. J. B. 107 and Bui. Myc. Fr. 7: 15, 1891. 

209 Potebnia, A., Ann. Myc. 8: 58, 1910. 

210 Hedgcock, G. G., J. Myc. 10: 2, 1904. 

2" Jaczewski, Bull. Acad. Sc. Cracow 1892, 1893, 1894. 

212 Cobb, N. A., Hawaii B. 5: 93, 1906, Sugar Planters E.xpt. Sta. 

2'3 Atkinson, G. F., 0. E. S. B. 33: 308. 1896. 

21" Atkinson, G. F., Bui. Torrey Bot. CI. 18: 1891. 

2'5 Seribner, F. L., U. S. Dept. Agr. R. 355, 1887. 

2'« Atkinson, G. F., Ala. B. 41: 1893. 

21^ Atkinson, G. F., Bot. Gaz. 16: 61, 1891. 

2>8 Stewart, F. C, B. 328: 389, 1910. 

219 Halsted, B. D., N. J. R. 381, 1893. 

220 Rostrup, Tid. f. Skw. 17: 37, 1905. 

221 Notizblatt k. Botan. Gart. u. Mus. Berlin-Dahlem .!,: 297, 1907. 

222 Voligno, Ann. R. Acad. Agric. Torino J,8: 417, 1905. 

223 Rathay, E., Zeit. 4: 190, 1894. 

22" Johnson, J., Proc. Ry. Dublin Soc. N. S. 10: 153. 

226 Prillieux and Delacroix, Bull. Soc. M. d. Fr. 6: 113. 

228 Maublanc and Lasnier, Bull. Soc. M. d. Fr. 20: 167, 1904. 

22^ Rev. in E. S. R. 13: 259. 

228 Sheldon, J. L., J. Myc. 13: 138. 

223 Smith, E. F., J. Myc. 7: 36, 1891. 

230 Lawrence, W. H., Wash. B. 64: 1904. 



294 THE FUNGI WHICH CAUSE PLANT DISEASE 

2" Aderholcl, R., Landw. Jahr. 25: 875, 1896. 

232 Clinton, G. P., 111. B. 67: 1901. 

233 Aderholdt, R., C. Bak. 6: 593, 1900. 

234 Vuilleman, C. R. 108: 632, 1889. 

235 Cavara, Zeit. 3: 16, 1893. 

236 Frank, B., Zeit. 5: 10, 1895. 

237 Delacroix, G., Agr. Prat. Pays chauds, 7: 235, 1907. 
2.38 Wagner, Zeit. 6: 101, 1895. 

239 Oudemans, C. A., J. A. Proe. Soc. Sci. Konin. Akad. Wet. Amster- 
dam 3: 141. 

2« Halsted, B. D., N. J. R. 13: 290, 1892. 

2" Pammel, L. H., la. B. 116: 1910. 

2 '2 Diedicke, C. Bak. 9: 317, 1902, and 11: 52, 1904. 

2« Ravn, F. K., Zeit. 11: 1, 1901, and Zeit. 11: 13, 1901. 

244 Noack, Zeit. 15: 193, 1905. 

245 Viala and Ravaz, Rev. d. Vit. 197, 1894. 

246 Bubak, Nat. Zeit. f. For. u. Land. 8: 313. 

247 Stoneman, B., Bot. Gaz. 26. 

248 Spaulding and von Schrenk, B. P. I. B. U: 1903. 

249 Shear, C. L., So. 32: 808. 1910. 

260 Southworth, E. A., J. Myc. 6: 164, 1891. 

251 Clinton, G. P., 111. B. 69: 1902. 

252 Hasselbring, H., Bot. Gaz. 42: 135, 1906. 

253 BurriU, T. J. and Blair, J. C, 111. B. 77: 1902. 

254 BurriU, T. J., Sc. 16: 909, 1902, and 111. B. 118: 578, 1907. 

255 Hasselbring, H., Trans. 111. Hort. Soc. 36: 350, 1902. 

256 Sheldon, J. L., Sc. 22: 51, 1905. 

257 Osterwalder, A., C. Bak. 11: 225, 1904. 

258 Shear, C. L. and Wood, A. K., Bot. Gaz. J^3: 2,59, 1907. 

259 Patterson, F. W. and Charles, V. K., B. P. I. B. 171: 1910. 

260 Atkinson, G. F., N. Y. (Cornell) B. 49: 310, 1892. 

261 Halsted, B. D., N. J. "R. 11: 1890. 

262 Edgerton, C. W., Bot. Gaz. 45: 404, 1908. 

263 Sheldon, J. L., Sc. 21: 143, 1905. 

264 Sheldon, J. L., W. Va. B. 104: 1906. 

265 Southworth, E. A., J. Myc. 6: 100, 1890. 

266 Humphrey, J. E., Zeit. 1: 174, 1891. 

267 Atkinson, G. F., J. Myc. 6: 172, 1890. 

268 Edgerton, C. W., Mycol. 1: 115, 1909. 

269 Barre, H. W., S. C. R. 22: 1909. 

270 Atkinson, G. F., 0. E. S. B. 33: 1896. 



BIBLIOGRAPHY OF ASCOMYCETES 295 

"1 Bui. Sc. Myc. do France 18: 285, 1902. 

"2 Idem., m: 167, 1904. 

2" Tavel, F., J. Myc. 5: 53, 1889. 

"•• Klebahn, H., J. Wis. Bot. 41: 515, 1905. 

2" Klebahn, C. Bak. 15: 336, 1905. 

278 Frank, B., Zeit. 1: 17, 1891. 

"' Miyake, Bot. Mag. Tokyo 23: 1909. 

278 Edgerton, C. W., Bui. Tor. Bot. CI. 34: 593. 

2" Rolfs, F. M., Sc. ^^; 87, 1907. 

280 Rant, A., Zeit. 17: 177, 1907. 

281 Montemartini, L., Riv. Path. Veg. 4: 165, 1910. 

282 Delacroix, G., Bull. Soc. M. d. France, W: 142, 1904. 

283 Massee, Kew Bull. June, 1892. 

284 Humphrey, J. C, Mass. R. 10: 242, 1893. 

285 Grossenbacher, J. G. and Duggar, B. M., N. Y. (Geneva) B. IS: 1911. 
288 Fairchild, D. G., Bot. Gaz. 16: 262, 1891. 

287 Hasselbring, H., 111. B. 70: 225, 1902. 

288 Butler, E. J., Ann. Myc. 9: 36, 1911. 

283 Eulefeld, Natw. Zeit. F. & Land. 8: 527, 1910. 
2^0 Woronin, M. & Nawaschin, S., Zeit. 6: 129, 1896. 
2" Muller-Thiirgau, C. Bak. 6: 653, 1900. 

292 Ikeno, Flora, 92: 1, 1903. 

293 Quaintance, A. L., Ga. B. SO: 1900. 

294 Cordley, A. B., Ore. B. 57: 1899. 

295 Galloway, B. T., D. Ag. R. 349, 1888. 

296 Potebnia, A., Ann. Myc. 8: 79, 1910. 

297 Edgerton, C. W., Mycologia 2: 169, 1910. 

298 Clinton, G. P., Ct. R. 319, 1906. 

299 Spaulding, P., B. P. I. Circ. 35. 

300 Zimmerman, A., C. Bak. 8: 183, 1902. 

301 Miyake, I., Bot. Mag. 21: 1, 1907. 

302 Essed, Ann. Bot. 25: 343, 1911. 

303 Essed, Ann. Bot. 25: 364, 1911. 
30" Essed, Ann. Bot. 25: 367, 1911. 
308 Miyake, I., Bot. Mag. 23: 1909. 

308 Hegy, P., B. Soc. M. d. Fr. 27: 155, 1911. 

307 Ducomet, V., Ann. Ec. Nat. Agr. Rennes 2: 1. 

308 Potebnia, A. Ann. Myc. 8: 48, 1910. 

309 Potebnia, A., Ann. Myc. 8: 70, 1910. 

310 Halsted, B. D., N. J. R. 358, 1893. 

311 Rand, F. V., Phyto. 1: 133, 1911. 



296 THE FUNGI WHICH CAUSE PLANT DISEASE 

'12 Duggar, B. M., N. Y. (Cornell) B. U5: 1898. 

"=> Scribner, F. L., U. S. D. Agr. R. 341, 1887. 

31" Stewart, F. C, N. Y. (Geneva), B. 328: 387, 1910. 

315 Clinton, G. P. Ct., R. 307, 1906. 

316 Heald, F. D., Sc. 28: 624, 1906. 

317 Richardson, A. E. V., Jour. Dept. Agr. So. Aust. U: 466. 

318 U. S. Dept. Agr. R. 129, 1886. 

319 Atkinson, G. F., Ala. B. W- 1893. 

320 Atkinson, G. F., 0. E. S. B. 33: 293, 1896. 

321 Southworth, E. A., Dept. Agr. R. 407, 1890. 
3" Edgerton, C. W., Bot. Gaz. 45: 367, 1908. 

323 Galloway, B. T., U. S. Dept. Agr. R. 387, 1888. 
32" Shear, C. L., Phytop. 1: 116, 1911. 

325 Reddick, D., N. Y. (Cornell) B. 263: 13, 1909, and Reddick, D., 
Phytop. 1: 106, 1911. 

326 Griffon, E. and Maublanc, A., C. R. Sc. (Paris) 151: 1149, 1910. 

327 Sadebeck, Unt. u die Pilsegall, 1884. 

328 Metcalf, H., B. P. I. B. 121: IV, 1908. 

329 MetcaU^, H., & Collins, J. F., B. P. I. B. Ul: 5, 1909. 
33''Appel, see C. Bak. 11: 143. 

331 Stewart, F. C, N. Y. (Geneva) B. 328: 318, 1910. 

332 Appel 0. & Wallenweber, H. W., Arb. d. Kais. Biol Anst. f. Land 
Forst. 8: Heft, 1, 1910. 

333 Bernard, C, Bui. Dept. Agr. Indes, Neerl. 55, 1907. 
33" Rolfs, F. M., Mo. Fruit B. 17: 1910. 

335 N. Y. (Cornell) B. 15: 1889. 

336 Atkinson, G. F., Bui. Torrey Bot. Club 21: 224, and Bot. Gaz. 
16: 282, 1891. 

337 Noack, F., Zeit. 9: 18, 1899. 

338 McAlpine, D., Dept. Agr. Melborne 1.32, 1899. 

339 Zimmerman, A., C. Bak. 8: 148, 1898. 
3« See Arnaud, G., Ann. Myc. 8: 471, 1910. 
3" Ann. Myc. 8: 472, 1910. 

3"2 Sheldon, J. L., Sc. 23: 851, 1906. 

3''3 Pammel, L. H., Proc. la. Acad. Sc. 7: 177, 1899. 

3"" Parker, J. B., Ohio Naturalist, 9: 509, 1909.. 

3"5 Griffon & Maublanc, B. S. M. d. Fr. 26: 371, 1910. 

3"6 Shear, C. L., Sc. 31: 748, 1910. 

3"7 Murrill, W. A., Torreya, 6: 189, 1906. 

3*8 Stone, G. E. & Smith, R. E., Mass. R. 57, 1901. 

3"9 Larsen, L. D. H., Sug. PI. Assn. B, 10, 



BIBLIOGRAPHY OF ASCOMYCETES 297 

350 Aderhold, R., Landw. Jahr. So: 875, 1896 and 29: 541, 1900. 

351 Brooks, F. J., Ann. Bot. ^: 285, 1910. 

352 Prillieux, E. and Delacroix, G., Bui. Soc. M. d. France, 9: 269, 
1893. 

353 Bull. Soc. My. d. Fr. 14: 24, 1898. 

354 Brefeld, Unt. 9. 



BASIDIOMYCETES (p. 64)Ufi8:«:5o;63:66:5l:6o'"' 



This class is distinguished from all others by its basidium, which 
typically is a sporophore bearing on its distal end short stalks, 

the sterigmata, usually four, 
on which are borne spores, 
basidiospores, one on the 
tip of each sterigma. Fig. 
215. In the great ma- 
jority of genera the basidia 
are typical and are clearly 
recognizable as such. 

In many of the lower 
basidiomycetes the basidia 
deviate somewhat from the 
typical form. Thus in the 
H e m i b a s i d i i, the smut 
fungi, the basidia are not 
typical in that they always 
arise from chlamydospores, 
not directly from the my- 
ceHum, Figs. 217, 231, and 
that they may produce more 
than the normal number 
from lateral, not terminal 




Fig. 215. — The typical basidium with sterig- 
mata and .spores in different stages of de- 
velopment. After De Bary. 



of four sporidia and these often 
sterigmata. 

The basidia in the large group of rust fungi are also atypical. 
The mycelium of the Basidiomycetes is septate and branched, 
and is always well developed. It is often found invading cells 
several meters from the sporogenous structures and frequently 
weaves together to form rhizomorphs. 

Peculiar cell connections known as clamp connections, or knee 
joints, Fig. 287, arc often found. The basidia in many genera are 

298 



THE FUNGI WHICH CAUSE PLANT DISEASE 



299 



borne on large complex sporophores composed of the mycelial 
threads interwoven to form a false 
parenchyma. The spores may 
germinate by tubes or by bud- 
ding. 

Typical sexuality seems en- 
tirely wanting, even rudimentary 
or vestigial sexual organs, cer- 
tainly recognizable, have not been 
found. The group is supposed in 
this regard, to represent the results 
of extreme simplification; the sex- 
ual organs to have long ago dis- 
appeared and the simple nuclear fusions that now exist to serve 
functionally as fertilization. 




Fig. 



216. — Ustilago spores showing 
development. After De Bary. 



Key to thk Subclasses of Basidiomycetes 

Chlamydospores at maturity free in a 
sorus, produced intercalary, from 
the mycelium ; basidiospores borne 
on a promycelium and simulating 

conidia I. Hemibasidii, p. 299. 

Chlamydospores absent or when present 
borne on definite stalks 
Basidia septate, arising from a rest- 
ing spore or borne directly on 

a hymenium 2. Protobasidii, p. 323. 

Basidia nonseptate, borne on a hy- 
menium 3. Eubasidii, p. 393. 

Hemibasidii 
The Hemibasidii contain one order. 



Ustilaginales 



45, 47, 124, 126-129, 131, 137 



Parasitic fungi, smut producers, mycelium consisting of hyaline, 
somewhat septate, branched, mostly intercellular filaments, 
practically limited to the interior of the host; at maturity often 



300 



THE FUNGI WHICH CAUSE PLANT DISEASE 



disappearing partially or wholly through gelatinization; fertile my- 
celium compacting into masses and giving rise to numerous chlam- 
ydospores formed from its contents. Conidia rarely develop on 
the exterior of the host. Sori prominent, usually forming dusty or 
agglutinated spore-masses that break out in definite places on the 
host or more rarely remain permanently embedded in the tissues. 
Spores (chlamydospores) light to dark colored, single, in pairs, 
or in spore-balls, the latter often composed in part of sterile cells. 
The Ustilaginales are all parasites on higher flowering plants. 
The vegetative mycelium is mostly inconspicuous and is often 



tb'h 






Fig. 217. — Ustilago. 2, promycelium with nucleus in mi- 
tosis; 5, with 4 nuclei; 6, with conidia. After Harper. 



distributed very widely in the host plant without giving external 
evidence of its presence until time of spore formation. It sends 
variously formed botryose or spherical haustoria into the host 
cells. At time of maturity of the fungus, the mycelium develops 
in great abundance at certain special places in the host, often in 
the ovary, leading to the development of large mycelial structures 
in the place of the host tissue. 

The chlamydospores develop directly from the vegetative my- 
celium; new and numerous transverse cell-walls are formed; the 
resulting short cells swell, round off and become coated with a 
gelatinous envelope. This later disappears and the spores develop 
a new, thick, usually dark, double wall which is variously marked. 



THE FUNGI WHICH CAUSE PLANT DISEASE 301 

The chlamydospores may be simple or compound, fertile or in 
part sterile and are variously shaped and marked as described in 
the genera below. 

The chlamydospores may germinate at once or after a more or 
less protracted rest interval. In germination in water or nutrient 
solution (manure water, etc.) a short tube is protruded, the pro- 
mycelium, this cUffering in character in the two families, Figs. 217, 
231. From the promycelium of most species there develop conidia, 
(often called sporidia) 1-12 or even more. The promycelium is 
regarded as homologous with the basidium of the other basidio- 
mycetes and the conidia as basidiospores. 

The conidia in suitable nutrient solutions often undergo repeated 
and indefinite budding closely simulating yeast cells in appearance. 
Fusion of conidia is not uncommon. 
Fig. 218. Conidia finding lodgment 7, -„^,, 

in suitable plant parts under suitable ^^ / ^i 

environmental conditions give rise to '^'' 

infection. The points at which in- -t) ' ' '^ -O ; 

fection can occur are very diverse 
with different species and will be 
considered under the separate species V VI,^ '- 

below. 

„, , ,. ,, 1 • 1 j^ Fig. 218. — Ustilago. 17, conidia 

The vegetative cells are bmucleate fusino'; 19, promyceiial cells 
in Tilletia, multinucleate in the Usti- ^^ h.sion tu^be.^apieai^^^^^^ dis- 

laginacese.^'^^® The young chlamydo- 
spores were shown by Dangeard ^'^^^ in the case of Doassansia, 
Entyloma, Ustilago and Urocystis to be binucleate. These two 
nuclei, according to Dangeard, later fuse rendering the mature 
spore uninucleate. In germination the one nucleus passes into 
the promyceUum, then divides mitotically Fig. 217, 2. A second 
division gives four nuclei (Fig. 217, 5) the spore nuclei.'* 

In the fusions of smut conidia Federly has found an accom- 
panying nuclear fusion, in salsify smut, while Lutman finds similar 
fusion in the conjugating promyceiial cells of oat smut.^ 

Whether or not these nuclear fusions represent a sexual act is 
a much controverted point. 

There are according to Clinton about four hundred species in 
America.^' -"* 



^y 



302 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Key to Families of Ustilaginales 

Promycelium usually with sporidia lateral 

at septa 1. Ustilaginaceae, p. 302. 

Promycelium with clustered terminal 

sporidia 2. Tilletiaceae, p. 314. 



Ustilaginaceae 

Sori usually forming exposed dusty or agglutinated spore- 
masses. Germination of chlamydospores by means of septate 
promycelia which give rise to terminal and lateral sporidia or else 
to infection-threads. 



Key to Genera of Ustilaginaceae 

Spores single 

Sori dusty at maturity 

Without definite false membrane 1. Ustilago, p. 303. 

With false membrane of definite fungous 

cells 2. Sphacelotheca, p. 310. 

Sori agglutinated at maturity 

Firmly agglutinated into conspicuous 

tubercular nodules 3. Melanopsichium. 

Developed around a central columella 

(rarely dusty) 4. Cintractia. 

Spores chiefly in pairs 

Sori agglutinated (on leaves) 5. Schizonella. 

Sori dusty (inside peduncles) 6. Mykosyrinx. 

Spores in balls of more than two 
Sori dusty or granular 
Spore-balls often evanescent; spores 

olive-brown or black-brown 7. Sorosporium, p. 312. 

Spore-balls rather permanent; spores 
yellowish or reddish, with markings 

only on free surface 8. Thecaphora, p. 313. 

Spore-balls quite permanent; spores ad- 
hering liy folds or thickenings of 
outer coat 9. Tolyposporium, p. 313 



THE FUNGI WHICH CAUSE PLANT DISEASE 



303 



Sori agglutinated 

Spore-balls (variable) composed of 

thick-walled spores 10. Tolyposporella. 

Spore-balls with peripheral spores and 

central sterile cells 11. Testicularia. 

Of these genera numbers three to eleven inclusive occur on un- 
important plants. Among them are: Polygonum, Rynchospora, 
Psilocary, Cyperus, Carex, Luzula, Juncus, Fimbrystylis, Cissis; 
various unimportant grasses, members of the Carcluacese, Faba- 
eeae, Nyctaginaceae, Amarantaceae, Cyperacese, Dracenacese, and 
Eriocaulacese. The most important genera are Ustilago and 
Sphacelotheca. 

Ustilago (Persoon) Roussel (p. 302) 

Sori on various parts of the hosts, at maturity forming dusty 
spore masses, usually dark colored ; spores single, produced irregu- 
larly in the fertile mycelial threads which early entirely disappear 
through gelatinization, small to medium in size; germination by 
means of a septate promycelium producing only infection-threads 
or with sporidia formed terminally and laterally near the septa; 
sporixiia in water usually germinate into infection-threads but in 
nutrient solutions multiply indefinitely, yeast- 4 

fashion. 

About two hundred species, seventy-two of 
which are given by Clinton ^ as occurring in 
America. Besides the species discussed below 
many others occurring upon grasses or other 
plants of minor value are omitted. 

U. avenffi (Pers.) Jens.^^. iie. ii7, 124, 125 

Sori in spikelets, rarely in leaves, forming a 
dusty olive-brown spore-mass, about 6-12 mm. Fig. 219.— u. aye- 

. nae, germinating 

long by half as wide, usually rather completely in water. After 
destroying floral parts, eventually becoming dissi- 
pated; spores lighter colored on one side, subspherical to spherical 
though often elongate, minutely echinulate, 5-9 ju in length, 
widespread on oats. 

The fungus was known by the name Ustilago as early as 1552 




304 THE FUNGI WHICH CAUSE PLANT DISEASE 

and was called U. avense in 1591. The species of Ustilago 
on oats, wheat and barley were considered identical until 
Jensen ^ showed that they are not intercommunicable. Wolff ® 
showed that seedlings can be infected through the first sheath 
leaf. Brefeld ^ studying infection more closely found it to be 
accomplished by germ tubes from sporidia and that plants are 
free from infection after the growing leaves have pushed one 
centimeter through the sheath leaf. The mycelium, after infec- 
tion, grows through the plant until blooming time when it seeks 
the ovaries and the enclosing glumes in which it forms a mycelial 
mass, which soon changes into spores. In nutrient solutions the 
conidia bud indefinitely, while on the host plant they produce 
infecting hyphse. 

Germination was first studied by Prevost.^ It occurs read- 
ily in water, a well de- 
veloped promycelium 
resulting in about 
twenty-four hours, 
Fig. 219. The sporidia 
are mostly narrowly 
elliptical. Fusion of 
sporidia is common. 
The promycelia are 
usually four-celled and 
occasionally branch, 
especially near the 
base. " ["«• ^-« 

U. crameri Korn.-'- 
Sori in the spikelets, 
infecting all of the 
spike, ovate, about 
2-4 mm. in length, 
chiefly destroying in- 

FiG. 220. — Growing point of the stem of barley. ' rl K 1 + • 

Much enlarged, showing smut mycelium. After ^^^ ana Dasai parts, 

^®^'*^®* spores reddish-brown, 

chiefly ovoid to subspherical though occasionally more elongate 
and irregular, smooth, with usually pitted contents, chiefly 8-11 m 
in length. 




THE FUNGI WHICH CAUSE PLANT DISEASE 305 

The promycelium is much branched but no sporidia are pro- 
duced. 

The smut commonly affects the ovaries of Panicum and Setaria, 
In America it has been collected on millet in several states. 

U. crus-galli T. & E.i^^ 

Sori often encircling stems at nodes or at the juncture of the 
inflorescence, infecting both stem and leaves, prominent, often 
nodular, one to several centimeters in length, protected by a tough 
hispid membrane which upon rupture discloses an olive-brown 
dusty spore-mass; spores ovoid to spherical, occasionally more 
elongate, rather bluntly echinulate or even verruculose, chiefly 
10-14 IX in length. 

On Panicum crus-galli throughout the United States. 

U. bulgarica Bub. is on Sorghum vulgare. European. 

U. medians Bieden, on barley, is closely like U. hordei.^^^ 

U. scorzonerae (A. & S.) Schr. on Scorzonera is very close to 
U. tragopogonis-pratensis. 

U. sacchari Rab.^^ 

Spore-mass black, spores globose or angularly globose, 8-18 n 
in diameter, olive-brown or rufous, epispore thick, smooth. 

On sugar-cane throughout the tropics, especially in the old 
world. 

In Java this fungus has been reported as the cause of serious 
damage. Barrett observed it in Trinidad, where the damage was 
less extensive. 

The leaves especially the young ones which have not yet sepa- 
rated from each other are the parts affected. From the upper part 
of the affected cane, as a rule, no secondary shoots arise, and those 
which do arise from the lower part become infected in their turn. 
The discolored whip-like structure at the end of an attacked cane 
becomes dusty and black and contains the spores of the fungus. 

U. hordei (Pers.) K. & S.^^- '''' '^^ 

Sori in spikelets, forming an adhering purple-black spore-mass, 
about 6-10 mm. in length, covered rather permanently by the trans- 
parent basal parts of the glumes ; spores lighter colored on one side, 
usually subspherical or spherical, smooth, 5-9 n, the most elongate 
rarely 9-11 /i in length. Common on barley. 

This was first recognized as distinct from the oat smut in 1591 



30.6 



THE FUNGI WHICH CAUSE PLANT DISEASE 



by Lobelius.^'' Persoon in 1801 first gave a definitely recognizable 
description.^^ In 1888 the species was separated from the other 
smut on barley. ^^ 

The spores germinate freely in water by one, rarely two, tubes, 
usually 4-celled, and produce abundant sporidia; these increase by 
budding, produce germ tubes, or fuse with each other. 
U. levis (K. & S.) Mag. 2^' ''' 

Sori in spikelets, forming a black-brown adhering spore-mass, 

sometimes small and entirely concealed by the 

3 f^ glumes but usually evident and destroying inner 

^ // and basal parts; spores lighter colored on one side, 

subspherical to spherical or rarely elongate, smooth, 

5-9 fjL, the most elongate rarely 11 /i in length. 

On oats throughout America and Europe, prob- 
ably more common than records show as it is very 
difficult to distinguish from U. avenae from which 
it differs chiefly in its smooth granular spores. 
U. macrospora Desm. 

Sori in leaves and glumes, generally showing as 
linear striae, but often more or less merged, at 
first covered by the epidermis, but this later rup- 
turing and disclosing black-brown dusty lines of 
spores; spores medium to dark reddish-brown, 
chiefly ovoid to spherical or occasionally some- 
what irregular and elongate, coarsely verrucose, at 
circumference usually showing the projections as 
tinted blunt scale-like appendages, sometimes even semi-reticulate, 
12-19 M in length. 
On various species of Agropyron in Europe and America. 
U. nuda (Jens.) K. & S.^^- ''' 

Sori in spikelets, forming a dusty olive-brown spore-mass, about 
6-10 mm. long by half as wide, temporarily protected by a thin 
membrane which soon becomes dissipated leaving the naked rachis 
behind; spores lighter colored on one side, minutely echinulate, 
subspherical to spherical or occasionally elongate, 5-9 n in length. 
In Europe and America. This smut on barley is distinguishable 
from the covered smut, U. hordei, by its olive-green spore-mass 
and by its early shedding of spores. As a rule, each spikelet, ex- 




FiG. 221.— U. le- 
vis, germina- 
tion in modi- 
fied C o h D ' s 
solution. Af- 
ter Clinton. 



THE FUNGI WHICH CAUSE PLANT DISEASE 307 

cept the awn and rachis is entirely transformed into smut. In 
water and in nutrient solutions the spores germinate by a single 
promycelium, 1 to 3-septate, and often branched, but without 
sporidia. That infection is floral in loose smut of both wheat and 
barley was first shown by Maddox ^^ and the fact was corrob- 
orated by Wakagawa,^^ Brefeld ^'^ and Hecke.^^' ^^ The my- 
celium has been demonstrated in the embryo by Broili.^^^ 

The spores falling between the glumes germinate, penetrate 
the ovary wall, and into the growing point of the embryo. The 
mycelium here lies dormant until the seed germinates, when it 
grows, keeping pace with the growing point throughout the season 
and finally invading the ovaries to produce its spores. 

The infection of the pistil, the penetration of the integuments 
and the nucellus and embryo sac was followed in microtome sec- 
tions by Lang.^-^ The embryo was reached by the mycelium some 
four weeks after infection of the pistil. In resting grains the my- 
celium is abundant in the scutellum as well as in 
all embryo parts except the roots. 

Cross inoculation by Freeman and Johnson ^^ 
from barley to wheat and the reverse gave 
negative results. The optimum time for infec- 
tion has been determined as the period of full 
bloom. 

U. perennans Rost.^-^' ^^^ 

Sori in spikelets, more or less destroying the 

, , J . , ,. ■ • Fig. 222.— U. tritici, 

basal and mner parts, sometimes even runnmg germination in 
down on pedicels, oblong, about 3-8 mm. in modified John's 

' . solution. After 

length, with dusty, olive-brown spore masses; Keilcmian and 
mycelium perennial in perennial parts of host; 
spores chiefly subspherical or spherical, occasionally ovate to el- 
lipsoidal, usually lighter colored on one side, more or less 
minutely echinulate, especially on the lighter side, 5-8 ^t in 
length. 

On the tall oat grass throughout its range. 

U. rabenhorstiana Kiihn occurs on several species of Panicum. 

U. tritici (Pers.) Rost-^-"' '''' 124, 125. 128 

Sori in spikelets, forming a dusty olive-brown spore-mass, about 
8-12 mm. long by half as wide, usually entirely destroying floral 




308 



THE FUNGI WHICH CAUSE PLANT DISEASE 



parts and eventually becoming dissipated and leaving behind only 
the naked rachis; spores lighter colored on one side, usually sub- 
spherical to spherical, occasionally elongate, minutely echinulate 
especially on the lighter side, 5-9 n in length. On wheat where- 
ever cultivated. 

The smut mass is covered at first by a very delicate membrane. 
Infection is floral as described for U. nuda. 

The spores germinate in water by a long 2 to 3, or even 6 to 
7-septate, promycelium, often curved. In nutrient solutions the 




FiG; 223. — U. zese, stages in spore development. After Knowles. 



promycelium branches profusely but sporidia are few or are en- 
tirely absent. 

U. zeae (Beck.) Ung.^^' 2^' '''-'-'' '''' '''' ^^^ 

Sori on any part of the corn plant usually prominent, forming 
irregular swellings from a few millimeters to over a decimeter in 
diameter, at first protected by a sort of false white membrane 
composed of plant cells and semi-gelatinized fungous threads, 
soon rupturing and disclosing a reddish-brown spore-mass; spores 
ellipsoidal to spherical or rarely more irregular, prominently 
though rather bluntly echinulate, 8-11 n the most elongate 15 /x 
in length. 

The germination of the spores, which occurs but poorly in water, 
was first studied by Kiihn 2° in 1857. In 1874 Kiihn saw the pene- 
tration of the germ tubes through the epidermis of the corn plant. 
Brefeld showed that the spores germinate well in nutrient solu- 
tions and that secondary spores are formed; also that corn can be 
infected by the sporidia at any point on its surface above ground 



THE FUNGI WHICH CAUSE PLANT DISEASE 



309 



when the tissues are soft and actively growing; and that infection 
is local on the host.~^ 

It is now known that the chlamydospores are capable of ger- 
mination without hibernation and that they remain viable one, 
two, perhaps more 
years. It was shown 
by Brefeld in 1895 
that the chlamydo- 
spores produce conidia 
in the air freely. It 
is these, air-borne, 
arising from spores 
on the ground, ma- 
nure, etc., which are 
chiefly responsible for 
infection. They must 
reach the plant on a 
susceptible part and 
under suitable con- 
ditions of moisture. 
The germ tubes from 
the conidia penetrate 
the epidermis, grow 
through or between 
the cells, Fig. 223, 
with an irregular my- 
celium which branches 
profusely and calls forth great hypertrophy of the surrounding 
host tissue. In sporing, the mycelium forms a great number of 
short, slender, irregular branches which make up a close tangled 
network in the diseased tissue. These slender branches swell, 
gelatinize, and portions of them round off as spores. Fig. 223. 

U. striaeformis (West.) Niess.-^' ^'"^ 

Sori in leaves, sheaths and rarely in the inflorescence, from short 
to linear, often extending, apparently by terminal fusion, for 
several centimeters, also occasionally fusing laterally to cover most 
of the leaf; at first covered by the epidermis but this is soon rup- 
tured and dusty brown to black, linear masses of spores become 




Fig. 224. — U. zese. 1, germination after three days in 
water; 2, similar but in air showing air sporidia. 
After Clinton. 



310 THE FUNGI WHICH CAUSE PLANT DISEASE 

scattered and the leaves become shredded; spores usually ellip- 
soidal to spherical, occasionally irregular, prominently echinulate, 
chiefly 9-14 ^u in length. 

It appears to be perennial. The spores germinate sparsely. 
The promycelium is long, branched, septate, and produces no 
conidia. 

On numerous species of grass, including red top, timothy and 
species of Poa and Festuca throughout Europe and America. 

Species of less importance, not all found in America are: 

U. schiriana Hem. which attacks bamboo; "^ 

U. secalis Rab. is European on rye; possibly a Tilletia. 

U. esculenta P. Hen. which causes swellings on Zizania which 
are eaten in the orient; 

U. vaillantii Tul. in the sexual organs of the Liliacese; 

U. panici-miliacei (Pers.) Wint. on Panicum miliaceum; 

U. tragopogi-pratensis (Pers.) Wint. on the flowers of Trago- 
pogon; 

U. cruenta Kiihn, widespread in Europe on sorghum; 

U. violacea (Pers.) Fcl. on the anthers of various members of 
the Caryophyllacese; 

U. tulipae Wint. on tulips and related hosts; 

U. vrieseana Vuill. on eucalyptus roots, a very doubtful species; 

U. sphaerogena Burr, on Panicum crus-galli. 

The fungus described as U. fischeri Pers. from Italy on corn 
is a Sterigmatocystis as is also U. phoenicis Corda on date fruits 
and U. ficuum Reich on figs. 

Sphacelotheca De Bary (p. 302) 

Sori usually in the inflorescence, often limited to the ovaries, 
provided with a definite, more or less temporary, false membrane, 
covering a dusty spore-mass; and a central columella, usually 
formed chiefly of the host plant's tissues. The false membrane 
is composed largely or entirely of sterile fungous cells which are 
hyaline or slightly tinted, oblong to spherical, and usually more 
or less firmly bound together; spores single, usually reddish-brown, 
developed in a somewhat centripetal manner as in Cintractia, 
small to medium in size; germination as in Ustilago. 

Sixteen species are recorded by Clinton for America. Of these 



THE FUNGI WHICH CAUSE PLAxXT DISEASE 



311 







f^fi 



only three are of economic importance. By Engler and Prantl, the 
genus is not separated from Ustilago. 

Sphacelotheca sorghi (Lk.) Ci.^^' ^^^ ^^s. ne. lu 

Sori usually in the ovaries or stamens forming oblong to ovate 
bodies 3-12 mm. in length (rarely fusing the very young spikelets 
into irregular forms), protected for 
some time by a false membrane 
upon the rupture of which the 
olive-brown spore-mass becomes 
scattered, leaving naked the dis- 
tinct columella of plant tissue. 
The sterile cells of the membrane 
break up to some extent into 
groups, hyaline, oblong to sub- 
spherical, chiefly 7-18 /x in length; 
spores subspherical to spherical, 
smooth, contents often granular, 
5.5 — 8.5 fi in diameter. 

On Johnson grass and sorghum 
throughout the world. The young 
pistil and usually the stamens as 
well are displaced by the fungous 
mycelium, the two being often 
blended together. The spores ger- 
minate readily in water, either 
when fresh or a year old, showing 
papillae in from three to ten hours. 
The promycelium is 2 to 3-septate 
and from the ends of one or more 
of its cells narrow tubes appear. 

These later fuse with the adjacent cell, forming the ''buckle 
joints." Either infection tubes or sporidia may also arise from 
the promycelium. Infection is possible only with young plants. 

The mycelium in the host plant grows rapidly into long irregu- 
lar, hyaline, thin-walled threads 2-4 mm. thick, which run through 
and between the cells. It is most abundant in the parenchyma, 
advancing especially through the pith region with the growth of 
the host. The young ovaries and stamens are eventually reached 



X)\ 






Fig. 2125. — S. sorghi, cross-section 
through base of young infected 
body (ovary), a, false membrane 
of epidermal cells and sterile my- 
celium, b, mature spores, b ', im- 
mature spores, c, columella. After 
Clinton. 



312 



THE FUNGI WHICH CAUSE PLANT DISEASE 




and the mycelium there develops richly under the epidermis. The 

outer cells remain sterile and constitute the membrane; the inner 

gelatinize and develop into spores. 
S. reiliana (Kuhn) Cl.^^' '''' '''• '''' '^^ 

Sori very prominent forming irregular masses including more or 
less of the entire panicle, usually 
5-15 cm. in length; often at first pro- 
tected by the leaf-sheath. A whitish 
false membrane encloses the black- 
brown spore-mass and the ray-like re- 
mains of the peduncles or columellas. 
In time it becomes ruptured and the 
spores scattered. Sterile cells are also 

Fig. 226.— s. reiliana. Ger- scattered in groups through the spore- 
mination in water. After mass, chiefly subspherical, 7-15 u in 

Hitchcock and Norton. ' -^ ^ ' ^ 

diameter; spores somewhat opaque, 
chiefly subspherical to spherical or occasionally ovoid or slightly 
angled, minutely but abundantly vcrruculose, 9-14 /j. in length. 

This is a cosmopolitan but comparatively rare form on corn, 
affecting the ovaries. It occurs also on sorghum. In germination 
a 3 to 4-celled, often branched, promycelium is formed and conidia 
are produced. 

S. diplospora (E. & E.) CI. is found on Panicum crus-galli and 
related grasses in the lower Mississippi Valley. 

Sorosporium Rudolphi (p. 302) 

Sori in various parts of the host, forming dusty, dark colored 
spore-masses; spore-balls of medium size com- 
posed of numerous fertile cells, often rather 
loosely united and frequently at maturity com- 
pletely separating; spores usually olive or 
reddish-brown, of medium size; germination 
similar to that of Ustilago; sometimes with 
elongate germ thread and no sporidia. 

Several species are parasitic on the coarser 
range grasses. S. consanguineum E. & E., 
S. everhartii Ell. & Gall., and S. ellisii Winter, are probably the 
most important. S. dianthi Rab. is found on Dianthus. 




Fig. 227. — Sorospo- 
rium. Spore mass. 
After Dietel. 




THE FUNGI WHICH CAUSE PLANT DISEASE 313 



Thecaphora Fingerhuth (p. 302) 

Sori in various parts of the host, often as indefinite masses in 
the floral parts or forming rather firm pustules on the stem, at ma- 
turity with a dusty spore- 
mass; spore-balls composed 
of few to many fertile cells, 
of small to large size; rather 
permanently united; spores 
usually yellowish or reddish, 

smooth on contiguous sides Fig. 228.— Thecaphora, spore ball germina- 

but usually marked on the *^°^- ^^^^'^ ^^^^*^^'^- 

free surface; germination, so far as known, by means of a single 

sporidium at the tip of the elongate septate promycelium. 

A small genus of slight economic importance. 

T. deformans Dur. & IM.i-*'' '-^ 

Sori in the seeds, showing when the legumes are broken open 
as reddish-brown, dusty spore-masses which destroy most of the 
seeds; spore-balls reddish-brown, ovoid to spherical, rather firm, 
composed of 3-25 (usually 7-12) spores, chiefly 27-60 /j. in length; 
spores in optical section triangular to polygonal or when free 
irregular oblong, free surface with papillae that sometimes vary to 
spiny processes, 15-25 ^i, chiefly 15-20 fx in length. 

On a large number of Leguminous hosts, including species of 
Vicia, Lathyrus, Lupinus, Trifolium, etc., in widely scattered 
regions of both the old and the new world. 

Tolyposporium Woronin (p. 302) 

Sori usually in the inflorescence, especially the ovary, forming 
granular spore-masses at maturity; spore-balls dark-colored, of 
numerous spores permanently united, germination about as in 
Ustilago. 

A genus of about ten species. 

T. bullatum Schr.i^s- 154 

Sori in ovaries, infecting occasional ones, ovate, about 3-5 mm. 
in length, covered with a thin, greenish, smooth membrane, upon 
rupture of which the black granular spore-mass becomes scattered ; 




314 THE FUNGI WHICH CAUSE PLANT DISEASE 

spore-balls black, opaque, oblong 
to spherical or polyhedral, usually 
containing one hundred or more 
firmly agglutinated spores, chiefly 
50-180 M in length; spores from 
nearly hyaline, to light reddish- 
brown, outer coat more or less 
folded in ridges, often spiny, ovoid 
to subspherical or polyhedral, 
chiefly 7-10 ijl or rarely 12 ^u in 

Fig. 229. — Tolyposporium. Spore length. 

ball germination. After Bref eld. ^ t-. • n- • 

On Panicum crus-galli m the 
United States east of the Rocky Mountains also in Europe. 
T. filiferum and T. volkensii, occur on sorghum in Africa. 

Tilletiaceae (p. 302) 

Sori either forming dusty erumpent spore-masses or permanently 
embedded in the tissues. Germination by means of a short promy- 
celium which usually gives rise to a terminal cluster of elongate 
sporidia, that, with or without fusing in pairs, produce similar 
or dissimilar secondary sporidia or germinate directly into infection 
threads. 

The American Tilletiaceae embrace nine genera and about one 
hundred twenty-five species. 

Key to Genera of Tilletiaceae 
Spores single 

Sori dusty at maturity 

Spores without a conspicuous hyaline 

appendage 1. Tilletia, p. 315. 

Spores with an elongate hyaline append- 
age 2. Neovossia. 

Sori permanently embedded in the tissues 

Sori definite, small 3. Entyloma, p. 320. 

Sori indefinite, large 4. Melanotaenium. 

Spores in balls 

Sori dusty; spore-balls with sterile cor- 
tex 5. Urocystis, p. 318. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



315 



Sori rather permanently embedded in 
tissues 
Spore-balls without sterile cortex 
Spore-balls consisting entirely of 

dark-colored spores 6. Tuburcinia. 

Spore-balls consisting of light-colored 
spores 
Spore-balls with or without central 

sterile cells 7. Burrillia. 

Spore-balls with central network of 

filaments 8. Tracya. 

Spore-balls with sterile cortex 9. Doassansia, p. 322. 

Neovossia occurs on Phragmites; Tuburcinia on Convallariacese, 
Primula, Trientalis and Geranium in Russia; Burrillia on Limnan- 
themum, Echinodorus and Sagittaria; Tracya on Spirodela. 



Tilletia Tulasne ^'^ (p. 314) 

Sori in various parts of the hosts, usually in the ovaries, forming 
dusty spore-masses; spores single and usually formed singly in 
the ends of the mycelial threads 
which disappear more or less 
completely through gelatiniza- 
tion, germination usually by a 
short promycelium which bears 
a terminal cluster of elongate 
sporidia that in nutrient solu- 
tions, with or without fusing in 
pairs, may give rise to a con- 
siderable mycelium bearing sec- 
ondary air-sporidia. 

The genus closely resembles 
Ustilago except in its larger Fig. 230. 
spores and mode of germination 

Tw^enty-two American species are listed by Clinton 
are of economic importance. 

T. pancicii Bub. & Ran. is reported on barley heads in Servia.^^ 

T. glomerulata. Cocc. & Mor. is a doubtful species on alfalfa. 




T. ftt'teiis, spores. Photo- 
micrograph. After Clinton. 

Only three 



316 



THE FUNGI WHICH CAUSE PLANT DISEASE 



T. foetens. (B. & C.) Trel.-^' '-'' ''-'• ''' 

Sori in ovaries, ovate or oblong, 5-8 mm. in length, more or 
less concealed by the glumes, all or only part of the ovaries of 
a spike infected; spores light to dark-brown, oblong to chiefly sub- 
spherical or spherical, occasionally somewhat angular, foetid, es- 
pecially when young, smooth, chiefly 16-22 fj,, the most elongate 
rarely 28 n in length. 

On wheat wherever grown. 

Kiihn "'^ found that infection occurs as in oats in the very 
young plants. From the infection point 
the mycelium approaches the growing 
point and follows the development of 
its host, sending its branches into each 
spikelet and finally into the growing 
ovules. Here it develops a close knot 
and in the ends of the threads and in the 
short branches the spores form. The 
spores germinate by a rather long, con- 
tinuous, thick promycelium on the tip of 
which a crown of long slender conidia de- 
velops. The sporidia soon become arched 
and often fuse in pairs; they develop in- 
fection threads. 

T. tritici (Beij.) Wint.^^s 
Sori in ovaries, ovate to oblong, 5-8 mm. 
which have united. One in length, more or less concealed by the 

has produced a secondary up i t 

sporidium at X and this is glumes; sterile cells lew, hyalme, sub- 
thread^ °"A.fter Freeman spherical, with medium-thin wall, smaller 
and stedman. ^^^n the fertile cells which are chiefly 

subspherical, light to dark-brown, with winged reticulations 
about 1 iJL high by 2-4 /j, wide, and 16-22 n in diameter. 
On wheat everywhere. 

Experiments have shown this distinct from T. foetans which it 
closely resembles except for its reticulate spores. 
T. texanaLong: Cl.^^g 

Sori in ovaries, ovoid or oblong, al^out 3-5 mm. in length, more 
or less hidden by enveloping glumes, forming a somewhat agglu- 
tinated light-reddish-brown spore-mass; sterile cells not very 




Fig. 231.— T. fretens. A, 
germinating spore produc- 
ing sporidia; B, Sporidia 



THE FUNGI WHICH CAUSE PLANT DISEASE 



317 



numerous, hyaline, witli very thick, often lameUate walls; fertile 
cells very light colored, orange-yellow appearing as if immature, 
chiefly subspherical or spherical, with prominent conical tubercles 
which extend out 2 3 ^x to the hyaline envelope, chiefly 19-25 n 
in diameter (including envelope.) 

On Hordeum nodosum in Texas. 

T. hordei Kcke is an Asiatic form on Hordeum. 

T. secalis (Cda.) Kiihn. occurs on rye in Europe. ^^^ 

T. horrida Tak.^^' i^i. i49 

Sori in the ovaries more or less destroying them, completely 




Fig. 232. — Tillctia tritici. A. Two spores germinated in 
moist air, promycelium and conidia, several of which have 
fused in pairs. Secondary conidia at C. B. Spores ger- 
minated in water, promyceUa elongate, septate. The pro- 
toplasm passes over into the younger cells. After Tubeuf. 

concealed by enveloping glumes; spores usually present in different 
stages of development, the mature spores almost opaque, chiefly 
subspherical to spherical, with very coarse hyaline or slightly 
tinted, somewhat curved, scales which show at the circumference 
of the spore as a band about 2—4 ju wide and on its top as polyg- 
onal areas 2-3 m across; hyahne membrane more or less evident 
and often at one side in a short thread-like projection, 22-33 /x 
in length. 

Cross sections of stems bearing smutted heads reveal the my- 
celium in the chlorophyll parenchyma between the fibrous tissue.^^ 

On rice in America and Asia. 



318 



THE FUNGI WHICH CAUSE PLANT DISEASE 




Urocystis Rabenhorst "^ (p. 314) 

Sori usually in the leaves or stems, occasionally in other parts, 
producing dark-colored, usually dusty, spore-masses; 
spore-balls permanent, composed of an enveloping 
cortex of tinted sterile cells and usually one to 
Fic. 233.— Spore several interior fertile cells; fertile cells generally 

ymiL" After dark-colored; germination often by a short promyce- 

Thaxter. jj^^j-j^ which pro- 

duces terminally-grouped spori- 
dia; these give rise to similar 
secondary sporidia or to infec- 
tion-threads. 

Besides the forms discussed 
below, foreign species are listed 
on Anemone, Liliacese, Gladiolus, 
Primula, etc. 

U. cepulffi Frost.27' ^^' ^=^0' ''' 

Sori in leaves, forming isolated 
pustules or affecting them for 
the greater part of their length 
and breadth, sometimes occur- 
ring at their bases, in the bulbs. 
Upon rupture of the covering 
membrane a dusty black-brown 
spore-mass appears; spore-balls 
ovoid to spherical, 17-25 /jl in 
length; sterile cells tinted, ovoid 
to spherical, small, rather com- 
pletely covering the spores, 
usually 4-8 /j. in length; fertile 
cells reddish-brown, ovoid to 
spherical, usually 1, rarely 2 in 
a ball, chiefly 12-16 fjt, in length. 
On Allium. 

The first American description of the fungus was by Farlow ^^ 
in 1876. A second thorough paper was from Thaxter in 1889.^^ 

The mycelium grows between the host cells. At maturity lateral 




Fig. 234. — Spores of U. cepulce germi- 
nating. X, sporidia; 23, germinating 
conidium. After Tliaxter. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



319 



=4)==::;^ 




Fifi. 



235. — Successive 
stages in formation 
of spore balls. Af- 
ter Thaxter. 



outgrowths appear from the hyphae at various points. One of 
these assumes a somewhat spherical form and matures to the fertile 
spore, while the other branch or branches grow around it, Fig. 235, 
branching and dividing into joints which eventually round off to 
form the sterile exterior cells. Spores are 
known to live in soil for at least twelve years. ^^ 
A period of rest is necessary before they can 
germinate. In germination the central spore 
produces a single short hypha, commonly 
branched, on which the conidia are borne ter- 
minally and laterally. Fig. 234. Experiments 
by Thaxter indicate that infection is subter- 
ranean. 

U. occulta (Wal.) Rab.i^^' ''' 
Sori in leaves, especially in the sheaths, 
culms and inflorescence, forming linear striae 
usually of great length and often merged into 
a continuous stratum of dusty, reddish-black, spore-balls; spore- 
balls oblong to subspherical, 16-32 /j, in length; sterile cells 
often incompletely covering the spores, hyaline or yellowish, sub- 
spherical to oblong, usually with distended and uniformly thick- 
ened walls; fertile cells reddish-brown, oblong to subspherical, 
often flattened, smooth, 1 to 4 in a ball, 11-18 /x in length. 

On rye wherever cultivated, though not common in America. 
The seat of spore formation is most often on the stems or sheaths, 
though all aerial parts of the plant are susceptible. In the vege- 
tative parts the fungus is commonly found in 
the tissue between the vascular bundles. 
U. violse (Sow.) F. de W.^-^' "^' ''"^ 
Sori on stems, rootstocks, petioles and leaves 
forming prominent irregular swellings often sev- 
eral centimeters in length, rather permanently 
covered by the host tissues but upon rupture 
' disclosing black-brown spore-masses; spore-balls 
reddish-brown, rather irregular, oblong to subspherical, chiefly 
28-55 n in length; sterile cells yellowish-tinted with age, 6-10 /j. 
in length; fertile cells light reddish-brown, ovoid to spherical or 
polyhedral, chiefly 4-8 in a ball, mostly 11-15 jj. in length. 




320 THE FUNGI WHICH CAUSE PLANT DISEASE 

On violets. In America it has been reported in Canada, Min- 
nesota and Utah. 

U. anemones (Pers.) Wint.^"^ occurs on various species of Ranun- 
culacese in both the old and new world. 

U. agropyri (Preu.) Schr.^ 

Sori in various parts, commonly in leaves, forming striae, which 
may be distinct or cover the surface of the leaf; at first lead-colored 
and protected by the epidermis but soon rupturing and scatter- 
ing the reddish-brown spores; spore-balls oblong to subspherical, 
16-32 iJL in length; sterile cells hyaline to yellowish, oblong to 
subspherical, usually completely covering the fertile cells, outer 
wall thin and by collapsing giving a ridged effect to the covering; 
spores 1 or 2, rarely 3 or 4 in a ball, reddish-brown, oblong to sub- 
spherical, often flattened, smooth, 11-18 fx in length. 

On Agropyron and some other coarse grasses throughout the 
United States and Europe. 

U. colchici (Schl.) Rab.^^^ On various species of Liliacese but 
not on hosts of -economic importance in America. 

U. italica Speg. probably not a true smut, is injurious to 
acorns, chestnuts and the seeds of the white fir.^^ 

Species of less importance or non- American are: 

■U. gladioli (Req.) Sm. on Gladiolus; 

U. ornithogali Korn. on Ornithogalum; 

U. kemetiana Mag. in pansy ovaries; 

U. primulicola Mag. on primrose flowers. 

Entyloma De Bary ^^^' "s (p. 314) 

Sori usually foliar, generally forming discolored but not distorted 
areas, permanently embedded in the tissues; spores single, pro- 
duced terminally or intercalary in the mycelium which does not 
entirely disappear through gelatinization, free (sometimes irregu- 
larly adhering through pressure), hyaline to yellowish or reddish- 
yellow, rarely dark-colored, germination by a short promycelium 
bearing a terminal group of sporidia which usually conjugate in 
pairs and produce secondary sporidia or infection-threads; sporidia 
often formed by germination of the spores in situ, the promycelium 
protruding through the stomata. 

Twenty American species are recorded. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



321 



Foreign species are on Papaver, Ranunculus, Delphinium, Calen- 
dula, Thalictrum and several other hosts. 

E. betiphilum Bub. is described on beet seed capsules; ^^ 

E. lephroideum for the same host in France; 

E. calendulae (Oud.) de B. on Calendula. 

E. crastophilum Sacc." 

Sori in leaves, subcircular to linear, about 0.25-2 mm. in length, 
usually distinct though occasionally merged, black, long covered 
by the epidermis; spores dark-brown, tightly packed and adhering 




Fig. 237. — E. ellisii, chlamydospores germinating within 
the leaf tissue, sporidia superficial. After Halsted. 

more or less, chiefly ovoid to spherical or angled through pressure, 
rather thick-walled, 8-14 /x in length. 

On Poa, Phleum, Agrostis and other grasses in Europe and 
America. 

E. irregulare Joh. occurs on species of Poa in Europe and 
America; 

E. polysporum (Pk.) Farl. on various hosts including the com- 
mon sunflower. 

E. ellisii Hals.^i 

Sori in leaves, forming pale white spots, indefinitely limited, 
subconfluent; spores hyaline or slightly yellowish, clustered in the 
intercellular spaces beneath the stomata, spherical, thick-walled, 
(2-5 n) chiefly 16-20 n but varying from 11 to 25 ju in diameter; 
conidia hypophyllous, abundant, acicular, small, 10-14 fx by less 
than 1 )U. 

On spinach, New Jersey.^^' ^^^ 

The chlamydospores germinate in situ beneath the stomata 
and bear the sporidia on tufts of promycelia which emerge through 
the stomata, presenting much the appearance of a Hyphomycete. 



322 THE FUNGI WHICH CAUSE PLANT DISEASE 

E. australe Speg. 

Sori foliar, forming spots, yellowish to eventually dark, usually 
0.5-6 mm. in length; spores light to reddish-yellow, ovoid to 
spherical or sUghtly angled, chiefly 10-16 jj. in length; conidia 
linear, somewhat curved, usually 30-55 x 1-2 }x. 

Common and destructive on many species of Physalis and on 
Solanum, especially on some of the cultivated forms throughout 
the Americas and in Africa. 

E. fuscum Schr.^^^ 

Sori in leaves, about 2-6 mm. or by confluence much larger, 
spores light yellow to chestnut-brown, provided (especially when 
young) with a conspicuously swollen gelatinous envelope, smooth, 
chiefly 13-19 ix in length; the hypophyllous matted outgrowths 
usually show few conidia which are fusiform, single-celled or sep- 
tate, 10-22 X 3 At. 

It occurs on Papaver in Europe and Eastern North America. 

E. nymphaeae (Cunn.) Set.^^'' 

Sori in leaves, forming variable and irregular areas, usually 
most prominent on the under side, yellowish or with age reddish- 
brown, scattered or confluent; spores hyaline, ovoid to subspherical, 
usually apiculate and with the remains of the hypha as a basal 
appendix, smooth or under an immersion lens minutely verrucu- 
lose, 10-14 fx in length; conidia not observed but spores said to 
germinate in situ. 

On leaves of various water lilies in both the old and new world. 

Doassansia Cornu.^*^' "^ (p. 315) 

Sori in various parts of the host, usually 
in the leaves, rather permanently embedded 
in the tissues; spore-balls conspicuous, per- 
manent, consisting of a distinct cortical 
layer and a central mass of fertile cells en- 
T?,^ oQc T-. • tirely filHng the interior, or with the inner- 

jbiG. 238. — Doaswansia. -^ ° ' 

Part section through most cells Supplanted by parenchymatous 

a spore ball showing , i i i i i i i- 

sterile and fertile cells, cells or hyphal threads; spores hyalme or 

After Dietel. yellowish, with smooth, usually thin, walls; 

germination often in situ, by means of a short promycelium which 




THE FUNGI WHICH CAUSE PLANT DISEASE 323 

gives rise to a terminal group of elongate sporidia, these often 
bearing secondary and even tertiary groups. 

The only species of this genus which occur on economic plants 
are D. gossypii Lagerh.^- on cotton in Ecuador and D. niesslii 
de Toni (Niess) Schr. on Butomus. 

The following genera, which are usually referred doubtfully to 
the Ustilaginales will be found under "Genera of Unknown Af- 
finity" page 663. 

Graphiola Poit, on various palms. Schinzia Nag. on Solanum. 
Bornetina M. & V. on Vitis. 

Protobasidii (p. 299) 

The three orders which belong to this group are characterized 
by septate basidia. 

Key to Orders of Protobasidii 

Basidia with cross walls 

Basidia arising from chlamydospores, 

Life cycle polymorphic. Parasites 1. Uredinales, p. 323. 

Basidia not arising from chlamydospores 
Not polymorphic. Gelatinous sapro- 
phytes 2. Auriculariales, p. 392. 

Basidia with lengthwise partitions, gelat- 
inous saprophytes 3. Tremellales. 

Uredinales"' *'' ^^' ^°' ^^' ^'"'' ^"°-^^^' ''^' ^^^-^^^ * 

Small fungi, mostly microscopic, parasitic in the tissues of 
ferns and seed plants. Mycelium much branched, septate, and 
with haustoria. Spores borne in sori below the surface of the host, 
or rarely single within the host. Sori naked, enclosed by peridia 
or paraphyses, or embedded in a thin stroma. Spores of five mor- . 
phological sorts, not all present in every genus; (1) basidiospores, 
minute, thin-walled, without surface sculpturing, (2) pycniospores, 
small, smooth, of unknown function, (3) seciospores, verrucosely 
sculptured, borne in chains, (4) urediniospores, echinulately or 

* Arthur's terminology involving the words pycnium, spcium, urediniiim, 
telium and derivatives from these words, will be followed in the treatment of 
this order. 



324 



THE FUNGI WHICH CAUSE PLANT DISEASE 



verrucosely sculptured, borne singly, or sometimes in chains, 
(5) teliospores, smooth or variously sculptured but not echinulate, 
borne singly or in chains. In every species the mycelium even- 
tually gives rise to teliospores, which produce in germination 
four basidia, either remaining within the spore-cell or borne in 
the air on a short promycelium, each basidium supporting a single, 
stalked or sessile basidiospore. 

The order of some two thousand species, constituting the 
"rust" fungi, many of them living on cultivated plants of high 
value, is of great economic significance. Its members are strict, 
obligate, parasites which in no stage of the life except in the 
promycelial stage can develop other than on the living host. 
The complexities of the life histories of the species, with their five 
distinct spore forms, inhabiting at different seasonal periods two 

or even three different host 
plants, renders the order both 
difficult and exceedingly in- 
teresting. 

The life history of the most 
complete of these fungi may 
be stated as follows: 

I. ^cia (aecidia) and O. 
pycnia (often called spermo- 
gonia or pycnidia). The my- 
celium arising from a basidio- 
spore invades the host plant, 
and vegetates until vigor suf- 
ficient to spore formation is 
attained, meantime often pro- 
ducing local spotting, hyper- 
trophy, or other injury to the 
host. The mycelium then de- 
velops a stroma which pro- 
duces spore beds (sori) and ruptures the epidermis. These sori 
are usually deeply sunken in the host and cup-shaped and take 
the common name "cluster cups," Fig. 239, technically aecia or 
aecidia. The sporophores arise from a hyphal plexus at the base 
of the cup and the spores are borne catenulate in acropetal suc- 





FiG. 239. — ^^cium and pycnium. 
Tavel. 



After 



THE FUNGI WHICH CAUSE PLANT DISEASE 325 

cession. The whole structure is usually red or yellow. The outer 
layer of the cup usually consists of a palisade of sterile sporo- 
phores bearing sterile cells and constitutes the peridium. The 
aeciospores are usually nearly globular, or angular by compression, 
reddish and rough and sometimes bear germ pores. They are ca- 
pable of germination at once and on germination give rise to germ 
tubes which may infect susceptible hosts, leading to a mycelium. 
This in turn again produces sori which in some species may be 
secia, in others telia, but in most species, uredinia. 

Associated with the secia, occasionally with other spore forms, 
but never borne alone, are minute pycnia with sporophores 
arising from their walls and bases. These bear unicellular pycnio- 
spores. Sterile hairs usually protrude from the ostioles. The 
whole structure in gross appearance is much like the pycnidium 
of Phoma or Phyllosticta but it is reddish or orange in color. 
These pycnia were formerly often spoken of as " spermogonia " 
and the spores as "spermatia," due to the thought that they stood 
for degenerated male organs; a view supported by the fact that 
the spores were not observed to germinate. Germination -'^ has 
now been observed and there is no longer reason to regard them 
as sexual organs. 

II. Uredinia (uredo-sori). The seciospores may infect the 
same species of plant that produced the aeciospores (autoe- 
cious) or plants of an entirely different species (heteroecious). 
The mycelium produced by the seciospore develops within the 
host; usually remains local, and causes spotting. When it has 
attained sufficient vigor and age, usually after about two weeks, 
it produces a sub-epidermal hyphal plexus from which arises a bed 
of sporophores which bear unicellular, hyaline to brown, nearly 
globose, thin-walled, usually echinulate or rough spores, each with 
from 2 to 10 germ-pores variously placed. These are the ure- 
diniospores borne in uredinia (uredo-sori). They may germinate 
at once producing a germ tube which develops to a mycelium. 

These spores falling on susceptible tissues, by infection, usually 
stomatal, continue the production of uredinia and spread the 
disease. The urediniospores are usually short-lived and function 
to spread summer infection. They continue to form throughout 
the growing season. 



326 



THE FUNGI WHICH CAUSE PLANT DISEASE 



In a few species ^^^' ^^^ there are what are known as amphispores 
or resting forms of urediniospores provided with thickened walls. 
They have colorless contents and pedicels more persistent than 
those of the usual urediniospore. 

III. Telia (teleuto-sori). Toward the latter part of the grow- 
ing seasons another kind of spore appears, often in the same 
sorus with the urediniospore and from 
the same mycelium. It is of various 
forms in different genera, one or more- 
celled, varies in shape, thickness of 
wall, surface marking, color, etc., but 
is uniform in the character of the 
germination which is very different from 
that of any of the other rust-spores. 

In teliospore germination, typically 
each cell of the teliospore sends forth 
one germ tube. These tubes soon cease 
growth and by septation become 4-celled. 
Each cell then sends out a short branch 
(sterigma) on which there develops one 
round or oval, 1-celled, thin-walled spore, 
the basidiospore, often in this group 
called the sporidium. 

Morphologically the promyceUum is a 
basidium bearing its four sterigmata and 
Fig. 240.— termination of four basidiosporcs. Relationship is thus 
AfterSh!^ ^' '''^'''■^^'" shown on the one hand to the Ustilagi- 
nales, on the other hand to the Auricula- 
riales, an assumption that is borne out by cytological evidence. 
Deviations from the typical mode of germination are found in sev- 
eral genera mentioned below (e. g., Coleosporium). 

Basidiospores germinate immediately by germ tubes which on 
suitable hosts give rise again to a?cia and pycnia or in some 
species to other spore forms completing the life cycle. 

The most complex life cycle is thus seen to comprise pycnio- 
spores, seciospores, urediniospores, teliospores and basidiospores. 
For brevity the first four stages are commonly designated by 
the following symbols: 




THE FUNGI WHICH CAUSE PLANT DISEASE 



327 



0. Pycnia or pycnial stage 

1. iEcia or secial stage 

11. Uredinia or uredinia stage 

III. Telia or telial stage 

The spores in all cases, except those of the basidiospores and 




Fig. 241. — Ainiihispores, urediniospores and teliospore.^ i>l I'ik i inia vexans. 
After Holway. 

pycniospores arise by direct conversion of a mycelial cell into 
a spore, i. e., they are chlamydospores. 

Mesospore is a term applied to occasional unicellular forms of 
teliospores found in Puccinia and related genera which do not 
usually have unicellular teliospores. 

As has been said the pycniospores seem to be functionless 
though by some it is thought that they do function but that man 
has yet failed to find the conditions under which they readily 
germinate and cause infection. The secial stage appearing first, 
and thus commonly in the spring, is often called the " spring stage." 



328 THE FUNGI WHICH CAUSE PLANT DISEASE 

It serves as an early stage to propagate and spread the fungus. 
The uredinia often called the "summer stage" constitute the 
phase usually of longest duration and of most injury. Its function 
is preeminently to multiply and spread the fungus. 

The telia, often called the "winter stage," usually, but not al- 
ways, constitute the resting, hibernating stage. In many instances 
the teliospores must rest over winter before they are capable of 
germination. Classification is based primarily on the tehospores. 

While all five of the spore forms discussed above are typical of 
many species there are many other species which do not possess 
all of these forms or indeed which may possess only one spore form. 

Schroter for convenience groups the rusts, according to the 
spore forms that they show, under the following type names 
though it must be recognized that such grouping is purely arti- 
ficial and does not necessarily bring together closely related species. 

Eu-type 0, I, II, III present; 

Brachy-type O, II, III present; I omitted. 

Opsis-type 0, I, III present; II omitted. 

Hemi-type II, III present; O, I omitted. 

Micro-type only III present; germination only after 

a resting period. 
Lepto-type only III present; germination without a 

resting period. 

As examples of the above we have the following : 
Eu-type, Puccinia asparagi, 0, 1, II, and III, all on Aspar- 

agus. 
Brachy-type, Puccinia suaveolens, 0, II, and III, all on thistle. 
Opsis-tjTDC, Puccinia tragopogonis, O, I, and III, all on salsify. 
Hemi-type, Uromyces caryophyl- 

linus, II, and III, both on Di- 

anthus. 
Micro-type, Puccinia ribis. III, on Ribes. 

Lepto-type, Puccinia malvacea- 

rum. III, on hollyhock. 

Hundreds of the hemi-types will doubtless be revealed by study 
to be heteroecious eu-types. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



329 



Hetercecism.^-'' All of the examples just given are autoecious, 
i. e., all known spore forms are found on the same species of host 
plant. In many other rusts, however, heteroecism prevails, i. e., 
one stage of the fungus is found on one species of host and another 
stage upon another host; rarely three host plants are involved in 
the cycle. Aside from the rusts only one other fungus (Sclcrotinia 
ledi) is known to show heteroecism. 

Heteroecism has been experimentally proved in some one hun- 
dred and fifty cases and may be assumed to exist in many hun- 
dreds of cases not yet investigated. 

Examples of heteroecism are as follows: 



Stages O, I. 
Eu-type, Puccinia graminis, Berberis 

" rubigo-vera, Boraginaceae 
" sorghi, Oxalis 

Uromyces pisi, Euphorbia 

Opsis-type, Gymnosporangium 

macropus, Apple 

It frequently 
happens that part 
of the life cycle is 
passed upon a mo- 
nocotyledonous 
plant, the remain- 
der upon a dicoty- 
ledon. In such 
event it is more 
often the II and 
III stages that are 
on the monocoty- 
ledon while the O, 
I stages are on the 
dicotyledon; exam- 
ples of this are af- 
forded in the nu- 
m e r o u s rusts of 
grasses, sedges and rushes. 



Stages II, III. 

Wheat 

it 

Corn 
Pea 

Red cedar (III) 




Fig. 242. — Urediniospore of P. asparagi germinating on 
surface of plant, and separate spores. After Smith. 



In one group the pycnia and the 



330 



• THE FUNGI WHICH CAUSE PLANT DISEASE 



secia are on pines (Peridermium), while the other stages are 
on dicotyledons. In the Gymnosporangiums the pycnial and 
secial stages are on Rosacese; the tehal on Juniperus and its kin. 
While a few general rules can be worked out concerning host 
relations there are many exceptions and to know one stage of 
a hetercecious rust generally gives little or no clue to what its 
complementary host may be. 

The mycelium of the rusts is usually intercellular and local though 
in a few instances it is extensive and even perennial in the host. It is 
abundantly branched, closely septate, gives off haustoria and usually 
bears numerous oil drops which lend a yellow or orange color. 

Irritation by the mycelium often induces marked hypertrophy 
or even witches' brooms or other deformation of the host. Hy- 
pertrophy is most common with the secia but may result 

from the telia as 
well, as is conspicu- 
ously shown in the 
genus Gymnospor- 
angium. In some 
instances the whole 
habit of the host 
plant is altered by 
the presence of the 
mycelium so as to 
render it almost un- 
recognizable, e. g., 
the secium of Uro- 

FiG. 243. — Cross-section, showing infection from spore Tr^-,Tna^ t-.i"oi* /\-n 1?n 
of P. asparagi. After Smith. myCCS piSl OH £iU- 

phorbia. 

The host cells are seldom killed by the mycelium, which ab- 
stracts its food supply from the carbohydrates and other nutrients 
of the cell sap without direct injury to the protoplasm, though 
ultimately there is serious effect upon both growth of the host 
and its seed production. 

Cytology.179' 180. i89. 313-315 Dangeard ^^^ and Sappin-Trouffy ^^ 
showed that the mycelial cells of the rusts are binucleate, a condi- 
tion which begins just below the secium. The origin and signifi- 
cance of this condition is of much interest. 




THE FUNGI WHICH CAUSE PLANT DISEASE 



331 



In all of the rusts so far investigated that have an aecium or 
primary uredinium there is in the seeio-mycelium or the primary 
uredinio-mycelium a fusion of uninucleated cells, gametes. This 
cellular fusion is not, however, followed by a nuclear fusion until 
after long delay ; but the two nuclei remain in the fusion cell and 
when this cell divides both nuclei divide mitoticallj^ and simul- 
taneously but still independently of each other (conjugate division). 
This process continues through the aecial sporophores, or uredinial 
sporophores, and in the production of the spores, with the result 




i^<r:'^^,— C.TTt. 
(■©5/. — Cm, J. 



Fig. 244.— Showing 
conjugate nuclei and 
degenerating cells in 
conidiospore chain 
of ^Ecidium. After 
Sappin-Troufify. 





Fig. 245. — Gymnospo- 
rangium, clavariae- 
forme, mitosis of a 
nucleus in the promy- 
celium. After Black- 




FiG. 240. — Conjugate 
nuclear division in 
Gymnosporangium 
clavarii3eforme show- 
ing four chromatin 
masses. After 
Blackman. 



that the cells of all of these are binucleate. The conjugate divi- 
sion continues further through the uredinia and until teliospore 
formation occurs, the whole intervening series of cells being binu- 
cleate. Prior to the formation of the promycelium and in the 
teliospore the nuclei unite, reducing the cells again to an uninu- 
cleate condition. 

In rusts which have only teliospores the binucleate condition 
begins somewhere in the mycelium from which the teliospores 
arise. 

It is generally held that the cellular fusion is a sexual act 
with long delayed fusion of the sexual nuclei: and consequently 
that the uninucleate phase is the gametophyte; that the be- 



332 



THE FUNGI WHICH CAUSE PLANT DISEASE 



ginning of the binucleate condition marks the origin of the sporo- 
phyte. 

Biologic specialization ^^^' 1^2.174. 309 ^luch as is found in the Erys- 
iphales occurs also in the Uredinales. There are many species, each 
of which is found on a large number of hosts. Upon its numerous 
hosts the fungus may show no morphological variation, yet at- 





FiG. 247. — Conjugate nu- 
clear division in cells of 
P u c c i n i a podophylli. 
After Christman. 



Fig. 248. — Diagram- 
matic representation 
of fusion of nuclei 
in the teliospore. Af- 
ter Delacroix and 
Maublanc. 



tempts to inoculate from one host to another may uniformly give 
negative results. It further often occurs that one stage, e. g., 
the aecia of a species may grow upon only one host while the 
uredinia or telia may grow upon many different species of hosts; 
and in such cases that seciospores which have arisen on host X, 
from infection with spores from host A, are capable of infecting 
host A and that host only; while seciospores which have arisen 
on host X, by infection with spores from host B, are capable of 
infecting host B and only this host; and so on for numerous forms. 
Yet the uredinia and telia of these different races may be mor- 



THE FUNGI WHICH CAUSE PLANT DISEASE 



333 



phologically inseparable as are also their secia when grown upon 
their common host. 

An excellent example of such biologic specialization is offered 
in the common pine Periclermium. ^cia may be produced upon 
the pine by sowing of Coleosporium teliospores from Senecio, 
Campanula, Pulsatilla, etc., but the seciospores which develop 
on the pine are capable of in- 
fecting only those species of 
hosts from which the telio- 
spores were taken. 

Similarly Eriksson ^^^ has de- 
termined that though rusts 
from many grains can infect 
the barberry, the seciospores 
there produced are not capable 
of infecting plants of species 
other than those from which 
the fungus was derived, or at 
most they can infect but a 
very limited number of species. 

A further complication arises 
from the facts obtained through 
experiments in various coun- 
tries, which have shown that what is apparently the same species 
may consist of a large number of strains or varieties which be- 
have differently in different geographic areas. The stem rusts of 
wheat and barley, for instance, are very similar, interchanging 
hosts easily and being capable of transfer to various grasses in this 
country, though in Sweden the stem rust of wheat goes with 
difficulty to barley and rye, while the stem rusts of barley and 
rye interchange hosts very easily. 

Owing to the prominence of its author and its place in litera- 
ture a word may be given to the usually discredited mycoplasm 
theory i^*'!^^. 312 ^f Eriksson. This affirms the existence in the 
cells of wheat grain of an intimate mixture of rust protoplasm and 
host protoplasm. This mycoplasm may rest thus for months. 
Finally the host-cell nucleus becomes digested and the fungous 
plasm develops to a mycelium which proceeds to invade the sur- 




FiG. 249. — Urediniospores in Rubus show- 
ing nuclear conditions. After Black- 
man. 



334 THE FUNGI WHICH CAUSE PLANT DISEASE 

rounding tissues of the seedling as these develop on germination 
of the seed. 

Infection Experiments. Since the method of studying the 
rusts by observing their life histories in the laboratory where 
they are under complete control of the observer has assumed 
such prominence of late years the technique deserves notice. 
The first step is to find associated in the field the secia and 
other stages of a rust in such way as to suggest relation- 
ship between two forms hitherto unknown to be connected. 

Material of the rust is then collected and healthy host plants 
are also removed to the laboratory. If the teliospores are col- 
lected in the fall they are kept out of doors in cheese cloth bags 
till germination time in the spring. Whether collected in spring 
or fall the viability of the spores must be tested by sowing in a 
hanging drop of water. If germination is plentiful then the infec- 
tion experiment is made. First the suspected alternate host is 
sprayed with water to give the spores proper conditions for ger- 
mination, then masses of spores are placed directly on the plant 
by a scalpel and a bell jar is placed over the plant to assure a humid 
atmosphere. In from five to eight days yellow spots should indi- 
cate where the infection has taken place and in a short time 
pycnia and secia or other sori follow. In all infection work it is 
imperative to know that the plants used be not already infected 
in the field from another source. 

The secium is by some regarded as a structure whose function 
is to restore vigor to the rust fungus.^°^ On the other hand, 
Freeman and Johnson ^°^ found that in fifty-two generations 
of the fungus, without the intervention of aecia or telia there 
was no apparent diminution in the vitality of the uredinial 
generation. 

Form Genera. The telial stage is regarded as the highest 
stage of the rust fungus and is the one on which classification is 
often based. Thus an secium, uredinium, cseoma, etc., that is 
known to possess a telial form is regarded as part of the species 
indicated by its teliospore, e. g., ^cidium berberidis being part 
of Puccinia graminis has no specific identity but is regarded as 
a stage of P. graminis. 

There are numerous uredinia, secia and other non-telial forms 



THE FUNGI WHICH CAUSE PLANT DISEASE 335 

of which the telial stage is not yet known. It beconres neces- 
sary for the present, for convenience of reference, to have 
names by which to designate these forms. For this purpose the 
form-genera ^Ecidium Cseoma, Peridermium, Roesteha and Uredo 
are recognized. We group these under the heading Uredinales 
Imperfecti. 

Darluca and Tubercuhna, two imperfect fungi, are often found 
growing as parasites upon the rust fungi. 

Key to Families of Uredinales 

Teliospores in germination becoming 
4-celled, compacted laterally 
into waxy layers; walls of the 

spores weakly gelatinous 1. Coleosporiacese, p. 335. 

Teliospores germinating by a promy- 

celium 

Teliospores compacted laterally 

into a crust or column (rarely 

solitary within the tissues); 

walls of the spores firm 2. Melampsoraceae, p. 340. 

Teliospores free or fascicled; walls 
of the spores firm or with an 
outer hygroscopic layer cov- 
ered by cuticle 3. Pucciniaceae, p. 353. 

Teliospores unknown 4. Uredinales Imperfecti, p. 389. 

Coleosporiaceae 

Teliospores united in a one or two-layered waxy cushion, ses- 
sile or borne on a broad sac-like stalk and then at the beginning 
2-celled. Each original spore-cell divides to four super-imposed 
cells from each of which a simple sterigma emerges. This bears a 
large basichospore. 

The most important character is the peculiar mode of basidio- 
spore production, the 4-celled promycelium being formed within 
the spore. 

The family is of little economic importance except in its secial 
stage on conifers. 



336 THE FUNGI WHICH CAUSE PLANT DISEASE 



Key to Genera of Coleosporiaceae. 

Basidiospore spindle-shaped 1. Ochropsora, p. 336. 

Basidiospore ellipsoid 

Teliospores in a single layer 

Teliospore layer stronglj^ arched, form- 
ing minute knobs 2. Mikronegeria. 

Teliospore in a flat crust 3. Coleosporium, p. 336. 

Teliospores in a double layer, long- 
stalked 4. Chrysopsora. 

Teliospores in a columnar mass 5. Trichopsora. 

Ochropsora Dietel 

II. Urediniospores solitary. 

III. Teliospores in a waxy crust, loosely united, originally 
I-celled, later 4-celled, each cell bearing a single basidiospore on 
a simple sterigma. 

0. sorbi (Oud.) Diet. 

1. iEciospores (=JEi. leucospermum) on anemone. 
II and III. Urediniospores on Sorbus and Spirea. 

Coleosporium Levielle 

0. Pycnia flattish, linear, dehiscent by a slit, without ostiolar 
filaments. 

I (=Peridermium). JEcia erumpent, definite. Peri chum color- 
less with verrucose walls. Spores globose to oblong, with colorless 
walls, the outer part formed of densely packed, deciduous tubercles. 

II. Uredinia erumpent, definite, without peridium. Spores 
catenulate, globoid to oblong, pulverulent; wall colorless, closely 
verrucose, pores obscure. 

III. Telia indehiscent except through weathering, waxy, some- 
what indefinite, usually roundish. Spores sessile, 1-celled (by 
early division of the contents appearing 4-celled) ; wall smooth, 
colorless, thickened and gelatinous at apex. 

The genus is usually heteroecious. Arthur lists some twenty- 
four species for America. 

There are many biologic forms, morphologically indistinguish- 



THE FUNGI WHICH CAUSE PLANT DISEASE 



337 



able yet not inter-inoculable. The aecial stage is found on 
leaves of conifers, the telia on a large variety of hosts. 
C. ipomoeaB (Schw.) Burr. 

and I. Unknown. * 

II. Uredinia hypophyllous, widely scattered or somewhat 
clustered, 0.25-1 mm. across, early naked, orange-yellow fading to 
white, ruptured epidermis usually inconspicuous; spores ellipsoid, 
13-21 X 18-27 jjL, more or less angular and irregular; wall thin, 
1-1.5 fi, closely and noticeably verrucose. 

III. Telia hypophyllous, widely scattered, often confluent, pul- 
vinate, 0.5 mm. or less across, deep reddish-orange fading to pale- 
yellow; spores with wall swelling 20-40 n above; contents orange- 
yellow fading to colorless, oblong, or slightly clavate, 19-23 x 
60-80 ix, rounded or obtuse at both ends. 

Common on various Ipomoeas and their kin among them morn- 
ing glory and sweet potato. ^^^ 

C. soiidaginis (Schw.) Thiim.*'' '''"'" 

O. Pycnia amphigenous, scattered, numerous, originating be- 
tween mesophyll and cortical layer, noticeable, 0.3-0.5 mm. wide 
by 0.5-0.8 mm. long, dehiscent by a longitudinal slit, low-conoidal, 
80-100 Ai high. 

1 ( = Peridermium acicolum). JEcia. from a limited mycelium, 
amphigenous, numerous, scattered on discolored spots occupying 
part of a leaf, erumpent from longi- 
tudinal slits, tongue-shaped, 0.5-1 mm. 
long by 0.5-0.7 mm. high; peridium 
rupturing irregularly, moderately firm, 
white, cells overlapping, 35-45 /x long, 
not much narrower, walls transversely 
striate, inner coarsely verrucose, thick, 
5-6 fjL, outer less rough and somewhat 
thinner; spores ellipsoid, 20-25 x 
28-40 fi; wall colorless, closely and 
coarsely verrucose with deciduous tu- 
bercles which are directed away from a smooth spot extending 
up one side, thick, 2-3 /x on the smooth spot, increasing to 
5-6 fj, on the opposite side, including the tubercles. 

II. Uredinia hypophyllous, rarely also epiphyllous, irregularly 




Fig. 250. — Stages O. and I. of 
Coleosporium soiidaginis 

(Peridermium) on P i n u s 
rigida. After Clinton. 



338 THE FUNGI WHICH CAUSE PLANT DISEASE 

scattered, or at first somewhat gregarious and crowded, 0.3-0.5 mm. 
across, soon naked, yellow or orange-yellow, ruptured epidermis 
inconspicuous; spores ellipsoid or globoid, 17-22 by 20-30 n; 
wall rather thin, 1-2 fjL, closely and strongly verrucose; contents 
orange-yellow when fresh, fading to colorless. 

III. Telia hypophyllous, scattered irregularly or sometimes 
crowded and confluent, slightly elevated, 0.3-0.5 mm. across, 
reddish-orange; spores with wall swelling 30-40 /x thick above; 
contents orange-yellow fading to colorless, terete, 15-23 x 55- 
80 /JL, rounded or obtuse at both ends; basidiospores globoid or 
elliptical, about 12 x 18 fx, orange-yellow. 
I. ^cia on Pinus rigida. 

II and III. Uredinia and telia on Aster, Solidago and culti- 
vated aster (Callistephenis) ; widespread and common. The con- 
nection between the stages was demonstrated by inoculations by 
Clinton. i9«' ''' 

C. senecionis (Schum.) Fries. 

O. Pycnia amphigenous, scattered, numerous, originating be- 
tween mesophyll and cortical layer, noticeable, 0.2-0.3 mm. wide, 
0.5-1 mm. long, dehiscent by a longitudinal 
slit, 70-100 fx high. 

I (=Peridermium oblongisporium) . vEcia 
from a limited mycelium, amphigenous, bul- 
late, tongue-shaped, 1-2 mm. long, 0.7- 
1 mm. high, whitish; peridium rupturing ir- 
regularly, fragile, white, cells overlapping, outer 
and inner walls of same thickness, 3-4 jj,, outer 
smooth, inner moderately verrucose; spores 
Fig. 251.— "coleospo- broadly ellipsoid, 17-24 by 28-36 (jl, wall 
rium senecionis, colorless, thick, 3^ n, densely verrucose with 

showing germina- _ ' ' . 

tion of teiiospores. prominent elongate papillae. 

^ ^ * II. Uredinia hypophyllous, thickly scattered, 

about 0.5 mm. across; early naked, bright orange-yellow fading 
to pale-yellow, ruptured epidermis evident; spores elliptical- 
globoid or obovate-globoid, 17-21 by 20-27 /x; wall thin, 1- 
1.5 /x, evenly but not densely verrucose, with low papillae. 

III. Telia hypo-phyllous, scattered, often confluent, small, 0.3 
mm. across, brilliant orange-yellow fading to pale orange-yellow; 




THE FUNGI WHICH CAUSE PLANT DISEASE 339 

spores with wall swelling 15-25 /x thick above; contents orange- 
yellow fading to pale-yellow, clavate or clavate-oblong, 16-20 ])y 
60-83 /i, rounded at both ends or narrowed below. 

I. JEcia on Pinus sylvestris. 

II and III. Uredinia and telia on Senecio. What may be this 
same fungus is reported also on cultivated Cineraria.^^^ The 
teliospores hibernate in their dark-red sori producing promycelia 
in the spring. The sporidia bring about spring infection of the 
pine leaves and young twigs, later resulting in pycnia and secia. 
The connection of the forms was established by Wolff in 1872. 

L. pmi LTali. 

0. Pycnia unknown, probably wanting. 

III. Telia amphigenous, on yellow spots, usually near the tips 
of the leaves, long covered by the epidermis, 1-5 mm. long, or 
when confluent up to 10 mm. or more, reddish-orange fading to 
pale-yellow or dirty- white, ruptured epidermis inconspicuous; 
teliospores with . walls swelling 30-50 (j. above, and soon dis- 
appearing upon exposure; contents orange-yellow fading to nearly 
colorless, clavate, slender, 13-20 by 60-100 ^i, acute or rounded 
above, much narrowed below, sides wavy or irregular. 

This is set apart by Arthur as the type of a distinct genus, 
Gallowaya, based on the absence of spore forms other than the 
teliospores. 

It causes serious leaf loss on Pinus virginiana. 

C. campanulae (Pers.) Lev.^°" 

0. Pycnia amphigenous, scattered, numerous, originating be- 
tween mesophyll and cortical layer, noticeable, large, 0.2-0.4 mm. 
wide, 1-2 mm. long, dehiscent by a longitudinal slit, 90-110 fx 
high. 

I ( = Peridermium rostrupi). JEcia from a limited mycelium, 
amphigenous, scattered, 1-3 on discolored spots, bullate, tongue- 
shaped, large, 1-3 mm. long, 0.7-1.5 mm. high, yellow, fading to 
white; peridium rupturing irregularly, fragile, white, cells overlap- 
ping, outer and inner walls same thickness, about 4-6 n, outer 
smooth, inner moderately verrucose; spores broadly ellipsoid or 
globoid, 17-22 by 22-31 m; wall colorless, thin, 2-3.5 /x, densely 
verrucose, with prominent, elongate papillae. 

II. Uredinia hypophyllous, scattered, often confluent, 0.5-1 mm. 



340 THE FUNGI WHICH CAUSE PLANT DISEASE 

across, soon naked, orange-red fading to white, ruptured epidermis 
evident; spores ellipsoid, 18-23 by 20-30 n; wall thin, 1-1.5 /x, 
densely verrucose, with prominent, elongate papillae. 

III. Telia hypophyllous, scattered, often confluent, small, 0.2- 
0.5 mm. across, slightly elevated, blood-red, fading to pale brownish- 
yellow; spores with wall swelling 15-25 ^ thick above; contents 
orange-red fading to nearly colorless, cylindrical or clavate-oblong, 
17-24 by 55-85 n, rounded or obtuse at each end. 

and I on Pinus rigicla. 

II and III on Campanula and kin. 

There are numerous other species of less importance. 

Melampsoracese (p. 335) 

Telia. forming a more or less definite crust or column; teliospores 
compacted laterally into layers or rarely solitary in the tissues, 
sessile; wall firm or rarely with a gelatinous layer. 

The family is pf little importance. Its urediniqil and telial stages 
do slight injury on poplars and willows. 

Key to Genera of Melampsoraceae. 

Telia indehiscent. 

Sori all subcuticular; teliospores com- 
pacted in dense layers to form a crust ; 
secia when present without a perid- 
ium; uredinia when present without 
a peridium or with an imperfect 
one of paraphyses 
Teliospores in a single layer; uredinia 
with spores and paraphyses inter- 
mixed 1. Melampsora, p. 342. 

Teliospores in more than one layer 
Uredinia with peripheral paraphyses 

only 2. Physopella, p. 345. 

Uredinia without paraphyses 3. Bubakia. 

Pycnia subcuticular, other sori subepi- 
dermal, or the telia within the epider- 
mal cells or between the mesophyll 
cells; uredinia when present with a 
peridium 



THE FUNGI WHICH CAUSE PLANT DISEASE 341 

Teliospores approximating in a single 
layer witliin or beneath the epider- 
mis; urediniospores globoid to 
oblong 
Walls of the teliospores colored 
Urediniospores echinulate through- 
out 4. Pucciniastrum, p. 346. 

Urediniospores echinulate except at 

the apex 5. Melampsoridium,p.347. 

Walls of the tehospores colorless 

Urediniospores ecliinulate 6. Melampsorella, p. 348. 

Urediniospores verrucose 7. Hyalopsora. 

Tehospores solitary within the meso- 

phyll; urediniospores pointed .... 8. Uredinopsis. 
Telia erumpent, sori all subepidermal 
Tehospores compacted laterally; aecia 
when present with flattened perid- 
ium, rupturing apicaUy; uredinia 
when present with a dehcate perid- 
ium and catenulate spores 

With all spore forms in life cycle 9. Melampsoropsis, p. 349. 

With telia and pycnia only 

Promycelium of the ordinary type. 10. Chrysomyxa, p. 350. 
Promycelial cells changing directly 

to basidiospores 11. Barclayella. 

Teliospores often adhering and extruded 
in long columns; aecia when present 
with inflated peridium, dehiscence 
circumscissile ; uredinia when present, 
with peridium, spores home singly on 
pedicels. 
Teliospores 1 -celled 
Telia naked 

Telia forming columns 

Teliospores firmly united side- 
wise and endwise 12. Cronartium, p. 350. 

Teliospores loosely united later- 
ally, separating in disks .... 13. Alveolaria. 
Telia not extruded 

Wall brownish, thick 14. Baeodromus. 

Wall colorless, thin 15. Cerotelium. 



342 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Wall slightly colored 16. Cionothrix. 

Telia with a peridium 

Telia half projecting above the 

host surface 17. Dietelia. 

Telia sunken in the tissue of the 

host 18. Endophyllum, p. 353. 

Teliospores 2-celled 

Peridium present 19. Pucciniosita. 

Peridium none 20. Didymopsora. 



Melampsora Castaigne (p. 340) 

0. Pycnia half spherical. 

1. iEcia of caeoma-type, no peridium or paraphyses. 
II. Urediniospores solitary, membrane colorless. 

III. Teliospores 1-celled, rarely 
more, in flat irregularly limited 
crusts. Basidiospores spherical. 

The question of biologic speciali- 
zation is especially complicated in 
this genus. The uredinial and telial 
stages occur in abundance on wil- 
lows and poplars, the secial stage on 
a wide range of plants embracing 
gymnosperms, monocotyledons and 
dicotyledons. 

M. lini D. C. 

0. Pycnia amphigenous, numer- 
ous, scattered, inconspicuous, sub- 
epidermal, pale-yellow, flattened 
globoid or lens-shaped, 100-175 ix 
in diameter, 65-95 /x high; spores 
ellipsoid, 2-3 by 3-4 ix. 

1. ^Ecia chiefly hypophyllous, nu- 
merous, scattered, rounded, 0.2-0.4 mm. across, bright orange- 
yellow, conspicuous, formed between epidermis and mesophyll, 
soon naked, ruptured epidermis evident; spores globoid, 19-27 x 
21-28 IX.) wall colorless, thin, about 1 ix, finely and evenly verru- 
cose, with distinct papillae, pores not evident. 




Fig. 252. — Pucciiiiastrum goepper- 
tianum, showing g e r m i n a t i ng 
teliospores. After Hartig. 



THE FUNGI WHICH CAUSE PLANT DISEASE 343 

II. Uredinia amphigenous and caulicolous, scattered or some- 
what gregarious, often crowded, round or on stems elongate, 
0.3-0.5 mm. across, soon naked, reddish-yellow fading to nearly 
white, pulverulent, ruptured epidermis noticeable; spores broadly 
elliptical or obovate, 13-18 x 15-25 n, wall colorless, rather thin, 
2 yu, evenly and finely verrucose, with low papillae, pores equa- 
torial, obscure; paraphyses intermixed with the spores, capitate, 
large, 5-22 x 40-65 fi, smooth, wall thick. 

III. Telia amphigenous and caulicolous, scattered, often con- 
fluent, round or elongate, 0.2-0.5 mm. across, slightly elevated, 
reddish-brown becoming blackish; spores subepidermal, appressed 
into a single layer, prismatic, 1-celled, 10-20 x 42-50 fi; wall 
brown, smooth, thin, about 1 n, not thickened above. 

Autoecious on flax. Sometimes very injurious. -'^^ 
M. medusae Thiim. 

0. Pycnia chiefly epiphyllous, scattered or somewhat gregarious, 
minute, punctiform, pale-yellow, inconspicuous, subcuticular, 
hemispherical, 40-80 /j, in diameter, half as high. 

1. vEcia chiefly hypophyllous, scattered or somewhat grega- 
rious, small, 0.1-0.3 mm. broad, round or oblong, pale-yellow 
fading to white, inconspicuous, formed between epidermis and 
mesophyll, soon naked, pulverulent, ruptured epidermis notice- 
able; aeciospores globoid, 17-22 by 17-24 fx; wall colorless, thick, 
2.5-3 fjL, minutely verrucose, with minute crowded papillae, pores 
indistinct. 

II. Uredinia amphigenous, or only hypophyllous, scattered, 
roundish, small, 0.2-0.4 mm. across, early naked, somewhat pul- 
verulent, orange-yellow, fading to pale brownish-yellow, ruptured 
epidermis usually inconspicuous; urediniospores ellipsoid or 
obovate-ellipsoid, 15-18 by 22-30 fx, usually flattened laterally; 
wall colorless, 2.5-3 fx or up to 10 fx on the flattened sides, sparsely 
and evenly verrucose, with fine papillae, except on the flattened 
sides which are smooth; paraphyses numerous, intermixed with 
the spores, capitate, smooth, 40-65 /x long, head 14-25 /x broad, 
wall thick, 3-6 fx, peripheral paraphyses thinner-walled and more 
clavate. 

III. Telia amphigenous or only hypophyllous, scattered or 
somewhat confluent, irregularly roundish, small, 0.2-0.4 mm. 



344 THE FUNGI WHICH CAUSE PLANT DISEASE 

across, slightly elevated, light reddish-brown, becoming deep 
chocolate-brown, subepidermal; teliospores prismatic, 12-15 by 
30-45 jj.; wall smooth, cinnamon-brown, uniformly thin, 1 /x. 

and I on Larix, II and III on Populus. Common on all 
species of Populus and often doing serious damage by its early 
defoliation of the trees. 

M. bigelowii Thiim. with and I on Larix and II and III on 
Salix is quite similar to the preceding. It occurs on practically 
all species of willow. 

Other species not found in America are: 

M. allii-fragilis Kleb.^^^ 

1 on Allium vineale and A. sativum. 
II and III on Salix. 

M. allii-salicis albae Kleb.^^^ 

I on Allium. 

II and III on Willow. 
M. allii-populina Kleb.^^^ 

I on AlUum. 

II and III on Populus. 
M. klebahni Bub. 

I on Corydalis. 

II and III on Populus. 

M. larici-pentandrae Kleb.^^^ 

I on Larix. 

II and III on Salix. 

M. larici populina Kleb.'^^^ 

I on Larix. 

II and III on Populus. 
M. pinitorqua Rost.^^^ 

I ( = Cseoma pinitorquum) . The Cseoma-stage is quite de- 
structive to pine seedlings. The teliospores grow on Populus 
leaves. 

M. repentis Plow. 

I ( =Ci3eoma orchidis); on Orchis. II and Illon Salix. 

M. ribesii-viminalis Kleb.^^^ 

I on Ribes. II and III on Salix. 

M. rostrupii Wagn.^^^ 

I on Mercurialis. II and III on Populus. 



THE FUNGI WHICH CAUSE PLXnT DISEASE 345 

M. saxifragarum (D. C.) Schr. 
I and III on Saxifrages. 

Physopella Arthur (p. 340) 

Cycle of development imperfectly known; only uredinia and 
telia recognized, both subepidermal. Uredinia erumpent, definite, 
roundish, pulverulent, encircled by more or less clavate paraphyses 
which are often united at their bases, or wholly, into a pseudo- 
peridium opening by a central pore. Urediniospores borne singly 
on pedicels, obovate-globoid or ellipsoid; wall pale-yellow, echinu- 
late or rarely verrucose, pores obscure. Telia indehiscent, form- 
ing lenticular masses, two or more cells thick at center. Telio- 
spores 1-celled; walls smooth. 

P. vitis (Thiim.) Arth.*' 

II. Uredinia hypophyllous, scattered thickly over wide areas, 
round, minute, 0.1 mm. or less across, soon naked, arising between 
epidermis and mesophyll, surrounded by numerous incurved pa- 
raphyses, pulverulent, pale-yellow, fading to dirty white, ruptured 
epidermis inconspicuous; urediniospores broadly ellipsoid or obo- 
vate, 13-17 by 18-27 m; wall nearly colorless, thin, 1 /i, minutely 
and rather closely echinulate, pores obscure; paraphyses hyphoid, 
curved and irregular, 6-10 /x thick, 30-60 fx long, wall uniformly 
thin, 1 n, yellowish. 

III. Telia hypophyllous, scattered thickly over large areas, 
roundish, minute, 0.1-0.2 mm. across, indehiscent, 3 to 4-cells 
thick; teliospores ovoid, 12-15 by 20-30 ix, wall smooth, nearly 
colorless, thin, 1 /x or less. 

On grape leaves in Southern United States and West Indies. 
Also in South America and Japan. 

P. fici (Cast.) Arth." 

II. Uredinia hypophyllous, scattered thickly over large areas, 
roundish, usually small, 0.1-0.3 mm. across, or rarely larger, bullate, 
arising between epidermis and mesophyll, tardily dehiscent by cen- 
tral rupture, encircled by delicate, evanescent paraphyses, pulveru- 
lent, pale cinnamon-brown, ruptured epidermis overarching or 
erect; spores obovate-globoid, 14-20 by 18-27 ju) wall pale-yellow, 
thin, 1-1.5 M, sharply and rather sparsely echinulate, pores ob- 



346 THE FUNGI WHICH CAUSE PLANT DISEASE 

scure; paraphyses hyphoid, very delicate, collapsing, 60-80 n 
long, wall colorless, very thin, slightly thickened at apex, 1 fx. 

III. TeUa, unknown. 

II. On fig and osage orange. 

Pucciniastrum Otth. (p. 341) 

Heteroecious. The cycle of development includes pycnia, secia, 
uredinia and telia, with distinct alternating phases. 

0. Pycnia subcuticular, low-conoidal, without ostiolar filaments. 

1. JEicia erumpent, cylindrical. Peridium delicate, verrucosa 
on inner surface. Spores ellipsoid, verrucose except one side which 
is thinner and smooth. 

II. Uredinia barely protruding through the epidermis, dehis- 
cent by a central pore. Peridium hemispherical, delicate, cells 
longer at orifice. Spores borne singly on pedicels, obovate to 
ellipsoid ; wall colorless, echinulate, pores indistinct. 

III. Telia indehiscent, forming more or less evident layers in 
the epidermal cells or immediately beneath the epidermis. Spores 
oblong or prismatic, 2 to 4-celled by vertical partitions in two 
planes; wall smooth, colored. 

Arthur lists nine American species but none are very impor- 
tant. 

P. hydrangeae (B. & C.) Arth. 
and I. Unknown. 

II. Uredinia hypophyllous, scattered, round, small, 0.1-0.2 mm. 
across, dark-yellow fading to pale-yellow, ruptured epidermis 
inconspicuous, dehiscent by a central pore; peridium hemispher- 
ical, delicate, cells small, cuboid, walls uniformly thin, 1-1.5 /x, 
ostiolar cells slightly or not elongate, 10-16 n, barely pointed, 
walls thin, smooth; spores broadly elliptical or obovate, 12-18 
X 16-24 n; wall nearly colorless, thin, 1-1.5 fx, sparsely and 
strongly echinulate. 

III. Telia amphigenous, or chiefly epiphyllous, effused, or 
confluent into small angular groups, 0.3-0.8 mm. across, not 
raised, reddish-brown; spores forming a single layer within the 
epidermal cells, or sometimes between the epidermis and mes- 
ophyll, globoid, 22-28 x 24-28 n, wall dark cinnamon-brown, 
uniformly thin, 1.5-2 fx. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



347 



It is found in the uredinial and telial stages on Hydrangea on 
which it may l)e quite serious. '"- 
P. goeppertianum (J. Kuhn.) Kleb. 

I. ( =.E. coknnnare) on Abies leaves. Ill on Vaccinium. 
The secial stage is the destructive form. It has been found 




Fig. 253. — Melampsoridium, section through germinating 
teiium. After Tulasne. 

but a few times in America, -°^' ^^° while the telial stage is common. 
Fig. 252. 

P. pustulatum (Pers.) Diet. (=P. abieti-chamaenerii, P. epi- 
lobii.) 

and I on Abies. II and III on Epilobium. 
P. padi (Kze. & Schm.) Diet. 

1 ( = ^. strobilinum) on fir. 
II and III on Prunus padus. 

P. myrtilli (Schm.) Arth. is found in the uredinial and telial 
stages on various Vacciniums. 



Melampsoridium Klebahn (p. 341) 

0. Pycnia fiattened-conoidal, without ostiolar filaments. 

1. ^cia erumpent, subcylindrical. Peridium regularly dehis- 
cent, cells rhomboidal. Spores ellipsoid to globoid; wall colorless, 
thin, verrucose except one side which is thinner and smooth. 

II. Uredinia somewhat erumpent. Peridium firm, dehiscent 
by central pore; peridial cells isodiametric, those of orifice pro- 



348 THE FUNGI WHICH CAUSE PLANT DISEASE 

longed into sharp points. Spores borne singly on pedicels, ellipsoid; 
wall colorless, echinulate, pores indistinct. 

III. Telia indehiscent, forming evident layers immediately 
beneath the epidermis. Spores oblong or prismatic, 1-celled; 
wall smooth, slightly colored. 

M. betulae (Schlim.) Arth. occurs, O and I on larch, II and III on 
Betula. 

Melampsorella Schroter (p. 341) 

0. Pycnia hemispherical, without ostiolar filaments. 

1. ^cia erumpent, definite, oblong, buUate. Peridium color- 
less, with thin-walled cells. ^Eciospores elUpsoid; wall colorless, 
thin, verrucose, without smooth spot. 

II. Uredinia barely protruding through the epidermis, dehiscent 
by a central pore. Peridium hemispherical, delicate, cells slightly 
or not enlarged at orifice. Urediniospores borne singly on pedicels, 
obovate to ellipsoid; wall slightly colored, echinulate, pores ob- 
scure. 

III. Telia effused, indehiscent. Teliospores globoid to ellipsoid, 
1-celled; wall smooth, colorless, thin. 

M. elatina (A. & S.) Arth.-^^ 

0. Pycnia epiphyllous, few, scattered, punctiform, inconspicu- 
ous, subcuticular, not extending much into walls of epidermis, 
depressed-hemispherical, small, 100-130 m broad, 40-50 n high. 

1. J^^cia from a perennial mycelium, dwarfing the young shoots, 
and forming witches' brooms, hypophyllous, forming two ir- 
regular lines, deep-seated, wholly dropping out of the substratum 
at maturity, roundish or irregularly oblong, large, 0.5-1 mm. 
across, bladdery, soon open by falling away of the upper part; 
peridium colorless, dehiscence irregular, cells with thin inner and 
outer walls; seciospores broadly ellipsoid, or nearly globoid, 14- 
18 X 16-28 fj.; wall colorless, thin, 1-1.5 fx, closely and rather 
finely verrucose. 

II. Uredinia amphigenous, scattered or somewhat grouped, 
small, round, 0.1-0.4 mm. across, orange-red when fresh, pale- 
yellow when dry; peridium hemispherical, dehiscent by a small 
central orifice, cells elongate at sides, polygonal above, inner and 
outer walls same thickness; urediniospores ellipsoid or obovoid. 



THE FUNGI WHICH CAUSE PLANT DISEASE 349 

12-18 X 16-30 m; walls pale-yellow, rather thin, 1-1.5 n; sparsely 
echinulate with short conical points. 

III. Telia hypophyllous, on whitish or pale reddish spots; 
teliospores within the epidermal cells, 1-celled, short-cylindrical 
or polygonal, 13-20 ju broad; wall colorless, smooth, thin. 

I ( =Peridermium elatinum) on fir causing swelling, cankers and 
witches' brooms. 

II and III on various members of the pink family. 

All stages possess perennating mycelium. The secial stage 
is of most economic significance, producing witches' brooms of 
various sizes. The secia are formed only on the deformed needles 
of the witches' brooms. 

Melampsoropsis (Schroter) Arthur (p. 341) 

Cycle of development includes pycnia, secia, uredinia and telia, 
with distinct alternating phases; heteroecious. Pycnia and other 
sori subepidermal. 

0. Pycnia deep-seated, somewhat erumpent, flask-shaped. 

1. ^cia erumpent, flattened laterally. Peridium firm, outer 
wall of cells greatly thickened and transversely striate, inner wall 
smooth. iEciospores ellipsoid to globoid; wall colorless, coarsely 
verrucose with deciduous tubercles. 

II. Uredinia erumpent, pulverulent. Peridium very delicate, 
evanescent, sometimes wanting. Urediniospores catenulate, 
globoid to lanceolate; wall colorless, verrucose with somewhat 
deciduous tubercles, pores ol)scure. 

III. Telia erumpent, definite, roundish, waxy becoming vel- 
vety. Teliospores catenulate, 1-celied, oblong or cuboid; wall 
colorless, thin, smooth. 

M. rhododendri (D. C.) Arth. 

Uredinial and telial stages on Rhododendrons; pycnial and 
aecial stages ( = ^Ecidium abietinum) on Picea excelsa. 

The pycnia appear on fir leaves in spring and about a month 
later the secia. The aeciospores germinate upon the Rhododen- 
dron. The mycelium perennates in its evergreen leaves and 
produces the uredinial and telial stages, the former of which 
serves for dissemination. The basidiospores infect the young fir 
leaves. 




350 THE FUNGI WHICH CAUSE PLANT DISEASE 



Chrysomyxa linger (p. 341) 

III. Teliospores formed of a series of superimposed cells, of 

which the lower are sterile, 
forming flat or slightly ele- 
vated, orange or reddish, 
waxy, crusts. Germina- 
tion of the teliospore by a 
promycelium from each 
cell, which produces mostly 
four basidiospores. 
C. abietis (Wal.) Ung. 

Fig. 254 -Melampsoropsisrhododendri, section r^ y ^^j j^ f 

through tehum. After De Bary. 

yellow spots on spruce 
leaves and the basidiospores seem able to infect the same host. 
European. 

Cronartium Fries (p. 341) 

0. Pycnia deep-seated, broad and flat. 

I ( = Peridermium). ^Ecia erumpent, inflated. Peridium mem- 
branous, rupturing at the sides rather than above, 2-4 cells thick, 
outer surface smooth, inner verrucose. Spores ellipsoid; wall 
colorless, coarsely verrucose with deciduous tubercles, except a 
smooth spot on one side. 

II. Uredinia somewhat erumpent. Peridium moderately firm, 
rupturing above, upper part evanescent; peridial cells isodiametric. 
Spores borne singly on pedicels, globoid to ellipsoid ; wall nearly or 
quite colorless, echinulate, pores obscure. 

III. Telia erumpent, at first arising from the uredinia, the 
catenulate spores adhering to form a much extended, cylindrical or 
filiform column, horny when dry. Spores oblong to fusiform, 
1 -celled; wall slightly colored, thin, smooth. 

Five American species are recognized by Arthur. 
All knowTi secial stages are Peridermiums on stems of conifers. 
C. ribicola F. de Wal.^^^-^se. 297 

O. Pycnia caulicolous, scattered, honey-yellow, forming minute, 
bladdery swellings. Spores hyaline, ovoid to elliptical, 1.9-4.7 fj,. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



351 



I (=Peridermium strobi). ^cia caulicolous, causing fusiform 
swellings of the stem, rounded to elongate; peridium inflated, rup- 
turing at sides, thick, membranous. Spores ellipsoid to ovoid, 
18-20 X 22-23 ix, wall colorless, coarsely verrucose except on 
elongate smooth spot, 2-2.5 ^ thick, on smooth spot 3-3.5 fx 
thick. 

II. Uredinia hypophyllous, thickly scattered in groups, round, 
pustular, 0.1-0.3 mm., at first bright yellow; peridia delicate. 




Fig. 255. — Cronartium. A, urediuium; B, telium. 
After Tubeuf. 

Spores ellipsoid to obovate, 14-22 x 19-3.5 //, wall colorless, 
2-3 /i thick, sparsely and sharply echinulate. 

III. Telial columns hypophyllous, cylindrical, 125-150 ix thick, 
up to 2 mm. long, curved, bright orange-yellow, becoming brown- 
ish; spores oblong or cylindrical, 8-12 x 30-60 n; wall nearly 
colorless, smooth, rather thick, 2-3 /x. 

Heteroccious 0, I, on white pine, Pinus cembra and several 
other 5-leaved species; II and III on currant and gooseberry and 
several other species of Ril^es. 

The telial stage was first noted in Geneva, N. Y., in 1906.-^'' 
The rust is now known in some nine states. It has been known in 
Europe since 1854. Its effects are most serious in its secial stage, 
though the telial stage is very abundant and conspicuous. The 
generic connections of the forms was proved by Klebahn in 1888 
by inoculations. 

The mycelium is doubtfully perennial in Ribes and certainly is 
so in the bark of the pine. 



352 THE FUNGI WHICH CAUSE PLANT DISEASE 

C. comptoniae Arth. 

I (=Peridermium pyriforme) on Pinus trunks. Ill on Comp- 
tonia. 

The Peridermium is perennial in the trunks of the pine where 
it does considerable injury. Clinton sowed seciospores from pine 




P'iG. 256.— Croiuirtium comptoiiiui (Peridermium) on 
Pinus. After Clinton. 



on Comptonia and in about twelve days the uredinia began 
to appear. ^^^ 

C. quercus (Brond.) Schr. 

Heteroecions I ( = Peridermium cerebrum) on pine. Ill on 
oak. 

Successful inoculations were first reported by Shear, ^^^ later by 
Arthur and Hedgcock.^^'' Globoid swellings 5-25 cm. across are 
formed on pine trees. 

C. asclepiadeum (Wil.) Fries. 

Heteroecious I ( = Peridermium cornui) on Pinus silves- 
tris. 

II and III on Cynachum, Paeonia, Gentiana and several other 
hosts. European. 

The mycelium is perennial in pine twigs and gradually kills 
them. 



THE FUNGI WHICH CAUSE PLANT DISEASE 353 



Endophyllum Levielle (p. 342) 

The cycle of development includes only pycnia and telia, both 
subepidermal. 

O. Pycnia deep-seated, somewhat crumpent, flask-shaped, with 
ostiolar filaments. 

III. Telia bullate, definite, round, pulverulent. Peridium evan- 
escent, cells resembling spores but flattened. Spores catenulate or 
seemingly compacted without order, 1-celled, globoid to ellip- 
soid; wall colored, medium thick, verrucose. 

E. sempervivi (Alb. & Schw.) D. By. 

Pycnial and telial stages on species of Sempervivum. Myce- 
lium perennial in the host. 

Pucciniaceae (p. 335) 

Teliospores stalked (stalk sometimes short or evanescent) 
1-celled or with several cells in a row or several united to form a 
parasol-like head on a compound stalk; separate or gelatinous- 
embedded. Basidiospores formed from promycelia. ^Ecia with 
or without peridia. Urediniospores solitary. 

This is the largest and most important family of the order, in- 
lesting numerous valuable agricultural plants and causing enor- 
mous loss. The species are manifold and the complexities owing to 
polymorphism, heteroecism and biologic specialization are very 
great. 

Key to Genera of Pucciniaceae 

Teliospores united into a head on compound 
pedicles, or several sessile or stalked on 
a common simple pedicel; sori subcutic- 
ular or subepidermal; uredinia when 
present without peridium or encircling 
paraphyses. 
Teliospores united into a head on a com- 
pound pedicel 1. Ravenelia. 

Teliospores free, 1-4 on a simple pedicel, 
all but one lateral 
Teliospores flattened laterallj- 2. Dicheirinia. 



354 THE FUNGI WHICH CAUSE PLANT DISEASE 

Teliospores flattened above and be- 
low 3. Pileolaria. 

Teliospores not flattened, but uredinio- 

spores flattened laterally 4. Hemileia, p. 355. 

Teliospores free, 2-8 at apex of a common 
stalk 

With all spore forms 5. Tranzschelia, p. 356. 

With pyenia and teha only 6. Poly thelis. 

Teliospores not borne on a common pedicel, 
or united into heads. 
Teliospore wall with a more or less evi- 
dent gelatinous layer. 
Teliospores with evident gelatinous 
layer, pores lateral 

Teliospores 3-celled 7. Phragmopyxis. 

Teliospores 2-celled 8. Uropyxis. 

Teliospores with obscure gelatinous 
layer, pores apical. 
Teliospores with appendaged pedi- 
cels 9. Prospodium. 

Teliospores without appendaged 

pedicels 10. Nephlyctis. 

Teliospore wall without gelatinous layer 
Pyenia subcuticular, other sori sub- 
epidermal; secia when present with- 
out peridium; uredinia when pres- 
ent without peridium, but usually 
with encircling paraphyses. 
Teliospores mostly tuberculate, the 
pores more than one and lateral 

Tehospores 1-celled 11. Trachyspora. 

Tehospores with 3 or more cells 
clustered at the apex of the 
pedicel 

Teliospores 3-celled 12. Triphragmium, p. 358. 

Tehospores more than 3-celled . 13. Sphaerophragmium. 
Teliospores with more than three 

cells lineally arranged 14. Phragmidium, p. 358. 

Teliospores mostly smooth, the pores 
one in a cell and apical. 
Teliospores 1-celled 15. Spirechina. 



THE FUNGI WHICH CAUSE PLANT DISEASE 355 

Teliospores 2-celled Ki. Gymnoconia, p. 359. 

Teliospores 3 or more-celled. 

Without uredinia 17. Xenodochus, p. 3G1. 

Without secia IS. Kuehneola, p. 3G1. 

Sori all subepidermal; secia when 
present with a peridium ; ure- 
dinia when present with no 
peridium or rarely with en- 
circling paraphyses. 
Teliospores embedded in a more 

or less gelatinous matrix . . 19. Gymnosporangium, p. 361. 
Teliospores not embedded in a 

gelatinous matrix. 

Teliospores colorless 20. Eriosporangium. 

Teliospores colored 

Teliospores I-celled 21. Uromyces, p. 371. 

Teliospores 2-celled 22. Puccinia, p. 375. 

Hemileia Berkley & Brown (p. 354) 

Cycle of development imperfectly known; only uredinia and 
telia recognized, both subepidermal. 

n. Uredinia formed beneath the stomata, erumpent, without 
peridium or paraphyses, spores ])orne singly on short pedicels, 
which arise from a protruding hymenium of agglutinated hyphse, 
obovate, laterally flattened and dorsiventral ; wall pale-yellow, 
smooth on ventral side, papillose on dorsal side, pores obscure or 
absent. 

III. Telia replacing the uredinia. Spores borne singly on pedi- 
cels, 1-celled, napiform; wall nearly or 
quite colorless, smooth. "^ 

H. vastatrix Berk. & Br. 

II. Hypophyllous, thickly scattered, rhr^lllKXir 
or rarely somewhat circinate, very small, ciFf^^ c 

about 0.1 mm. across, light-orange fading ^^^ 257.-Hemileia vast a- 
to pale-yellow, pulverulent, projecting trix, a, uredinium; c, 

, , 1 , , 1 1 / • telio.spore. After D i e t e 1 

through stomata and rarely rupturmg and Ward. 

the epidermis; spores bilateral, slightly 

obovate, flattened on the ventral side, 20-28 by 30-40 m; wall 

pale-yellow, 1-1.5 ix thick, rather thickly and very coarsely papil- 




356 THE FUNGI WHICH CAUSE PLANT DISEASE 

lose on dorsal side with Ijliintly pointed tubercles 2-4/1 long, 
1-1.5 jLt in diameter, ventral side smooth, pores ol)scure. 

III. Hypophyllous, arising from uredinia, thickly scattered, 
very small, about 0.1 mm. across, pale-yellow; spores napiform 
or globoid, somewhat umbonate above; wall pale-j'ellow or seem- 
ingly colorless, thin, 1 jx, slightly if any thicker above, smooth; 
pedicel hyaline, one-half to once length of spore, slender. 

It constitutes a serious coffee parasite in the orient and is re- 
ported also from Porto Rico. 

H. woodii K. & C. is a serious coffee parasite and occurs also on 
Vanguieria edulis. 

H. oncidii Griff & Maub. is on cultivated Oncidiums in France. 

Tranzschelia Arthur (p. 354) 

Cycle of development includes pycnia, secia, uredinia and telia, 
with alternating phases; autoecious or hetercecious. Pycnia sub- 
cuticular, other sori subepidermal. 

0. 1. Pycnia depressed-conical or hemispherical; hymenium flat. 

^cia erumpent, cylindrical. Peridium dehiscent at apex, be- 
coming recurved. iEciospores globoid; wall colored, finely ver- 
rucose. 

II. Uredinia erumpent, definite, without peridium. Uredinio- 
spores borne singly on pedicels, with paraphyses intermixed, 
obovoid, somewhat narrowed at both ends; wall colored, usually 
paler below, echinulate; pores equatorial. 

III. Telia erumpent, definite, pulverulent, without peridium. 
Teliospores forming heads or balls by being attached b}^ short, 
fragile pedicels to a common stalk, which is short and incon- 
spicuous, 2-celled by transverse septum, cells rounded and easily 
falling apart, wall colored, verrucose. 

T. punctata (Pers.) Arth.^i' '~^^' 232. 233 

I (=^'Ecidium punctatum). Peridia uniformly scattered over 
the whole of the foliage, hypophyllous, flat, semi-immersed, 
with torn yellowish edges. Spores subglobose, pale yellowish- 
brown, 15-24 II in diameter. Pycnia scattered, blackish, puncti- 
form. 

II. Uredinia light-brown, small, round, crowded, pulverulent, 
often confluent. Spores ovate or subpyriform, apex darker, 



THE FUNGI WHICH CAUSE PLANT DISEASE 



357 



thickened, bluntly conical, closely echinulate, brown, 20-35 x 
12-16 jJL, mixed with numerous capitate brownish paraphyses. 

III. Telia pulverulent, dark-brown, almost black. Spores con- 
sisting of two spherical cells, flattened at their point of union, 
the lower cell often being smaller and paler. Epispore uniformly 




Fig. 25S. — T. punctata, urediuiusporos. Alter Holway. 



thick, chestnut-brown, thickly studded with short stout spines. 
Spores 30-45 x 17-25 ^i. Pedicels short, colorless. 

Heteroecious : and I on Hepatica and Anemone. 

II and III on Prunus sps., peach, almond, plum, cherry, apri- 
cot. 

Widely distributed in North America, Europe and Asia and 
apparently introduced into Australia about 1883. The secial stage 
is perennial. Urediniospores have also been shown to remain viable 
over winter. The peculiar character of the urediniospores has 
sometimes led this fungus to be mistaken for a Uromyces. 

In 1904, Tranzschel -^^ made cultures of the secial stage from 
Anemone on various Prunaceous hosts. Arthur made similar 
inoculation from Hepatica in 1906. 



358 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Triphragmium Link (p. 354) 

Teliospores 3-celled, one basal, tv/o apical, each cell with one 
or more germ tubes. 

T. ulmariae Schm. occurs on Ulmaria in England and at one 
station in America. 



Phragmidium Link (p. 354) 

O. Pycnia present. 

L iEciospores in l^asipetal chains. The first two spore forms 





Fig. 259. — Triphragmium ulmarias, germi- 
nating teliospore. After Tulasne. 



Fig. 260.— Phragmi- 
dium bulbosum, 
teliospore germi- 
nating. After Tu- 
lasne. 



are in pulverulent sori, surrounded by clavate or capitate, hyaline 
paraphyses. 

11. Urediniospores single. 

IIL Teliospores separate, pedicellate, consisting of from three 
to ten superimposed cells, the uppermost of which has a single 
apical germ pore, the others about four each, placed laterally. 

The secial stage is a Cseoma but with a border of incurved pa- 



THE FUNGI WHICH CAUSE PLANT DISEASE 



359 



raphyses. The unicellular urediniospores are similarly surrounded, 
and bear numerous germ pores. The genus is limited to Rosaceous 
hosts and its species are autoecious. 

Eight American forms are recognized by Arthur ^^^ on roses as 
follows: 

P. montivagum Arth., P. disciflorum (Tode) James, P. ameri- 




vo/ 






Fig. 261. — Uredinio- and teliospores of; 1. P. americanum ; 2. P. rosse-setigerae ; 3. P. rosae 
calif ornicse; 4. P. rosae-arkansanse ; 5. P. montivagum; 6. P. disciflorum. After Arthur. 

canum Diet., P. rosae-setigerae Diet., P. rosae-californicae Diet., 
P. rosae-arkansanae Diet., P. subcorticinum (Schr.) Went, and 
P. rosae-acicularis Sire. 

They are mostly on wild roses and of but little economic im- 
portance. 

P. violaceum (Schul.) Went, is often serious on Rubus in 
Europe. 

P. rubi-idaei (Pers.) Wint. is found on raspberries in Europe. 

P. speciosum Fr. on rose has been separated by Arthur as 
Earlea speciosa on account of its non-gelatinous teliospore pedi- 
cel, its large compact caulicolous telia and the absence of uredinia. 

Gymnoconia Lagerheim (p. 355) 

O. Pycnia conic. 

I ( =C8eoma), peridia and paraphyses none. 
III. Spores as in Puccinia. 

This genus bears a superficial resemblance to Puccinia but is 
easily distinguished by its naked secial sori. 



3G0 



THE FUNGI WHICPI CAUSE PLANT DISEASE 



G. interstitialis (Schl.) Lag.-^-"-'^' -^^ 

0. Pycnia glandular, numerous mostly epiphyllous. 

I (=Caeoma nitens), hypophyllous, sori irregular, confluent; 
spores orange-red, globose to elliptic, epispore thin, 18-35 x 12-24. 

III. Telia hypophyllous, few, sparse, cinnamon-brown; spores 
more or less angular, 36-45 x 22-27 [x, pedicel short or wanting. 

Autoecious, on raspberries and blackberries, wild and cultivated, 
in United States, Canada, Europe and Asia. 

The pycnial stage appears first in spring giving to the leaves 
and stems a glandular appearance. About two or three weeks 




Fig. 262. — G. interstitialis, cseoma sorus. After Newcomb. 

later the ajcial stage is visible on the lower surface of the leaves; 
the epidermis soon ruptures and the orange beds of spores show. 
The pycnia are then fully developed. The affected plants are 
much stunted and are unproductive but are not killed. The 
fungous mycelium is intercellular, growing rapidly into formative 
tissues and perennating -^^ in the woody shoots. The knob-like 
haustoria penetrate the cells and often lie against the nuclei. The 
mycelium is especially a])undant in the pith near the bundles. 

The ajciospores may germinate at once and infect susceptible 
hosts. The teliospore which is less conspicuous and therefore 
rarely seen is of the Puccinia type. The telia appear in July 



THE FUNGI WHICH CAUSE PLANT DISEASE 361 

and August, usually hypophyllous, and the sori are very small 
and inconspicuous. 

Artificial infection of Rubus with the spores of the Cseoma stage 
by Tranzschel -^^ gave rise to the telial form, demonstrating 
the identity of the two. Cultures were also made by Clinton 
about the same time. 

Xenodochus Sclilecht (p. 355) 

^ciospores catenulate; uredinia wanting; teliospores short- 
pedicelled, several celled in linear arrangement. 

X. carbonarium Schl., autoecious on Sanguisorba in Europe. 

Kuehneola Magnus (p. 355) 

iEcia wanting; uredinia pulvinate, telia similar to Phragmidium 
but with smooth spores with the germ pores apical. 
K. uredinis (Lk.) Arth. 

II. (=Uredo muelleri.) Uredinia lemon-yellow, minute dots; 
spores globose to elliptic, about 26 jjl, hyaline, slightly verrucose. 

III. Telia solitary, pale, 250-500 n broad; spores 5 to 6 to 
12-cclled, epispore hyaline, cells 17-47 x 15-26 At; basidiospores 
8.5-9.5 M- 

The telia are pale yellowish-white, thus readily distinguishing 
t'.iem from other Rubus rusts. 

The uredinia are common and sometimes injurious on Rubus. 
The sori are small and scattered. 

K. gossypii (Lagerh.) Arth. is reported on cotton in British 
Guiana,-^^ also Florida, Cuba and Porto Rico. 

Gymnosporangium Hedwig f.-oe-^n. 213. 217 (-p 355^ 

Cycle of development including pycnia, secia and telia, with 
distinct alternating phases; heteroecious and autoecious. Pycnia 
and other sori subepidermal. 

0. Pycnia deep-seated, usually globoid, generally prominent 
and conspicuous, at first honey yellow, usually becoming blackish, 
globose or flattened-globose, with ostiolar filaments. 

I (=Roestelia) erumpent, at first cylindric. Peridium dingy 
white, usually elongated into a tubular form, membranous, tending 



362 



THE FUNGI WHICH CAUSE PLANT DISEASE 



to rupture by longitudinal slits along the sides; peridial cells im- 
bricate and often articulated, occasionally hygroscopic, outer walls 
smooth, rather thin, inner walls smooth, verruculose, verrucose, 
rugose, or spinulose. iEciospores in basipetal chains with alter- 
nate barren cells, enclosed in a peridium, globoid to broadly ellip- 
soid; wall colored, verrucose, usually with numerous, scattered, 
evident germ pores. 

III. Telia erumpent, naked, usually definite, variously shaped, 
gelatinous and elastic at maturity, expanding considerably when 
moistened. Teliospores chiefly 2-celled, in some species 3, 4, or 




Fig. 263. — Gymnosporangium, spore masses just emerging. 
After Heald. 

5-celled, by transverse septa; walls colored, of various thickness, 
smooth; pores usually two in each cell, sometimes, 1, 3, or 4, vari- 
ously arranged; pedicels hyaline, elastic, usually of considerable 
length, cylindric, rarely carotiform, walls thick, the outer portion 
swelling and becoming gelatinous to form a jelly-like matryx in 
which the spores appear embedded. 

All of the species agree in possessing the same spore forms, 
pycnia, secia, and telia which appear in the same sequence in 
the different species; also, in the fact with two exceptions, that 
the aecia grow on pomaceous plants and the telia on Juniperus 
(with few exceptions). 



THE FUNGI WHICH CAUSE PLANT DISEASE 



363 



The fficiospores are borne in secia which rest in orange or 
yellow spots often strongly thickened. Pycnia aliound. The 
aecium with its thick peridium is erumpent and projects to 
some distance above 
the host surface, this 
character giving rise 
to the separate form- 
genus, Roestelia. The 
peridial margin which 
may be lacerate or 
fimbriate is used in 
specific characteriza- 
tion. The spores are 
borne and function as 
in ordinary secia. 
They bear several germ 
pores. 

iEciospores germi- 
nate at once and if 
they fall upon suitable 
coniferous hosts bring 
about infection. The 
mycelium penetrating 
the leaf or brancli 
often induces large 
hypertrophy. 

In spring in moist 
weather the telio- 
spores are found in 
spore masses com- 

, r j-v. Fig. 264. — Gymnosporangium teliospores. a, G. cla- 

posecl 01 tne spores, variaeforme; h, G. globosum; c, G. macropus; d, G. 
which are USUallv nidus-avis; c,G. nelsoni;/,G.clavipes. After King. 

orange or yellow, and of their long gelatinous pedicels. 

Each cell usually bears several germ pores near the septum 
through one of which the tube emerges. 

The teliospores germinate immediately in situ by typical 
4-celled promycelia and four basidiospores are produced on each 
promycelium. 




364 



THE FUNGI WHICH CAUSE PLANT DISEASE 



The basidiospores are capable of infecting only the appropriate 
alternate host and that when the parts are still young and 
tender. 

An abnormal development of germ tubes instead of the usual 
promycelium has been reported in some instances. According 
to Lloyd & Ridgway ^°^ several crops of basidiospores are pro- 
duced in one season. 

The various species usually make good subjects with which to 
study infection. The teliospore masses placed in water soon 
become covered with basidiospores. Suspensions of these in water 
applied to susceptible hosts usually give positive results readily. 

G. juniperi-virginianae Lk. ^°^' -^^' ^^^( = G. macropus) Schu. 

0. Pycnia epiphyllous. 

1. ^cia ( =RoesteUa pyrata) chiefly hypophyllous, usually in 
annular groups, on thickened discolored spots, at first cylindric, 

0.1-0.4 mm. in diameter; 
i^eridium splitting extremely 
early, becoming fimbriate to 
the base, strongly revolute; 
peridial- cells usually seen 
only in side view, long and 
narrow, 10-16 x 65-100 ju, 
becoming much curved when 
wet, inner and side walls 
rather sparsely rugose with 
ridges extending half way 
across the side walls; aecio- 
spores globoid or broadly 
ellipsoid, 16-24 x 21-31 n, 
wall light chestnut-brown, 
2-3 fx thick, finely verru- 
' ose. 

III. Telia appearing on 
globoid or reniform galls 
5-30 mm. or more in diam- 
eter, evenly disposed, cylindric or cylindric-acuminate, 1.5-3 mm. 
in diameter by 10-20 mm. long, golden-brown; teliospores 2-celled, 
rhombic-oval or narrowly ellipsoid, 15-21 x 42-65 m; slightly or 




Fig. 265. — G. juniperi-virginianae, aecia. 
After Heald. 



THE FUNGI WHICH 6^JSE PLANT DISEASE 365 

not constricted at the septum, wall pale cinnamon-brown, thin, 
about 1 jLt; pedicel cylindric, 3-5 /j. in diameter; pores two in 
each cell near the septum. 

I. iEcia on apple both wild and cultivated. 

III. Telia on Juniperus virginiana and J. barbadensis. 

Destructive, particularly in East and South. 

Sporidia are matured in twelve to twenty-four hours after the 
spore-masses expand by moisture and as soon as the sori begin to 
dry they are carried away by wind and on suitable hosts infect 
through the cell walls by appresoria. Two or three crops of sporidia 
may arise in one season but the first crop is largest.-^* Each crop 
may result in a corresponding crop of secia. The stage on apple 
fruits shows as pale-yellow spots of pinhead size about seven 
to ten days after infection. The spots finally become orange- 
colored and in a few weeks the pycnia appear as black specks. 
On leaves hypophyllous cushions 0.5-1 cm. in diameter form on the 
spots and bear the secia, the mature tubes of which are split and 
recurved giving a stellate appearance. yEciospores pass back to 
the cedar in summer and cause infection. The mycelium here 
remains practically dormant according to Heald ^^* until the fol- 
lowing spring when the telial galls first become visible. These 
galls grow throughout the summer, mature in the fall, and give 
rise to the teliospores during the next spring. The mycelium is 
thus seen to be biennial. 

G. clavarigeforme (Jacq.) D. C. ^oe. sos. 211 

I. vEcia hypophyllous, fructicolous or caulicolous, usually 
crowded in small groups 2-3 mm. across on the leaf blades, some- 
times in larger groups on the veins, petioles and twigs, often 
densely aggregated on the fruits and occupying part or all of the 
surface, cylindric, 0.7-1.5 mm. high by 0.3-0.5 mm. in diameter; 
peridium soon becoming lacerate, usually to base, erect or spread- 
ing; peridial cells long and narrow, often becoming curved when 
wet, linear in face view, 18-30 x 80-13 fx, linear or linear-oblong 
in side view, 15-25 fi thick, outer wall 1-2 n thick, smooth, inner 
wall and side walls 5-7 n thick, rather coarsely verrucose with 
roundish or irregular papilla? of varying sizes; seciospores globoid, 
21-27 X 25-30 fi, wall light cinnamon-brown, 2.5-3.5 n thick, 
moderately verrucose.- 




366 THE FUNGI WHICH CAUSE PLANT DISEASE 

III. Telia caulicolous, appearing on long fusiform swellings of 
various sized branches, numerous, scattered, or sometimes aggre- 
gated, cylindric, or slightly compressed, 5-10 mm. long by 0.8-1.5 
mm. in diameter, acutish, or sometimes forked at the apex, 
brownish-yellow; teliospores 2-celled, lanceolate, 13-20 x 40-80 n, 
occasionally longer, rounded or narrowed 
above, usually narrowed below, very 
slightly or not at all constricted at the 
septum, wall golden-yellow, thin, about 
1 n; pores 2 in each cell, near the sep- 
tum. 

I. JEcia on Crataegus spp., Amelanchier, 
Aronia, Cotoneaster, Cydonia, and Pyrus. 
III. Telia on Juniperus communis, J. 
Fig. 266. — Gymnosporan- oxycedrus, and J. sibirica. Spindle-shaped 
Stin^Xfpr^Jr:; sweUlngs occur on Juniper branches. 
Richards. CyUndric spore-masses ooze through rifts 

in the bark. ^Eciospores shed in June germinate at once on Juniper 
twigs and result in the following year in swellings which often 
later cause death. In spring the spore-masses emerge and the 
teliospores germinate in situ. Upon the Rosaceous hosts spots 
appear eight to fourteen days after infection. Kienitz-Gerloff 
reports the occasional formation of a germ tube instead of a 
promycelium. This is, however, to be regarded as an abnormal 
condition. 

G. globosum Farl. ^os- 213. 215. 216 

O. and I. ^Ecia chiefly hypophyllous and crowded irregularly 
or rarely in approximately annular groups 2-7 mm. across, cylin- 
dric, 1.5-3 mm. high by 0.1-0.2 mm. in diameter; peridium soon 
splitting in the upper part, becoming reticulate half way to base; 
peridial cells seen in both face and side views, broadly lanceolate 
in face view, 15-23 x 60-90 fi, linear rhomboid in side view, 13-19 n 
thick, outer wall about 1.5 ^t thick, smooth, inner and side walls 
3-5 ^i, thick, rather densely rugose with ridge-like papillae of 
varying length; aeciospores globoid or broadly ellipsoid, 15-19 x 
18-25 fx, wall light chestnut-brown, 1.5-2 /x thick, finely verru- 
cose. 

III. Telia caulicolous, appearing on irregular globoid, gall-like 



THE FUNGI WHICH CAUSE PLANT DISEASE 367 

excrescences 3-25 mm. in diameter, unevenly disposed, often 
separated by the scars of the sori of previous seasons, tongue or 
wedge-shaped, 1.5-3 mm. broad by 2-5 mm. long at the base and 
6-12 mm. high, chestnut-brown; teliospores 2-celled, ellipsoid, 
16-21 X 37-48 n, somewhat narrowed above and below, slightly 
constricted at the septum, wall pale cinnamon-brown, 1-2 /u, 
thick; pores 2 in each cell, near the septum. 

I. iEcia on apple, pear, Crataegus, quince, mountain ash. 

III. Telia on Juniperus virginiana and J. barbadensis. Common 
and widely distributed in eastern America. 

The telial galls are from 0.5 to 2.5 cm. in diameter, very ir- 
regular. In late spring dark-brown spore-masses, later yellow- 
orange, 0.5 to 2.5 cm. long appear. 

The Roestelia spots are 0.5-1.0 cm. across. Pycnia blackish 
above. The secia are on thickened hypophyllous spots, long, 
slender, soon splitting and becoming fimbriate. Mesospores occur 
occasionally. The seciospores germinate on the cedar. The 
mycelium stimulates the hosts to extra formation of parenchy- 
mateous tissue. 

G. juniperinum (L.) Mart. 

1. JEciix (= Roestelia penicillata [Pers.] Fries.) hj^pophyllous, 
in annular or crowded groups, 2-5 mm. across on large thickened 
discolored spots, at first cylindric, 0.5-1.5 mm. high, 0.5-1 mm. in 
diameter; peridium soon becoming finely fimbriate to base and 
somewhat twisted or incurved; peridial cells usually seen only in 
side view, rhomboid, very thick, 30-35 x 60-90 fi, outer wall 
medium thin, 2-3 n, smooth, inner wall medium thick, 7-10 /x, 
rugose, side walls very coarsely rugose with thick, somewhat 
irregular ridges, roundish or elongate ridge-like papillae inter- 
spersed; seciospores globoid, very large, 28-35 x 30-45 fx, wall 
chestnut-brown, thick, 3-5 /jl, rather finely verrucose. 

III. Telia caulicolous, appearing on hemispheric swellings 
(1-4 cm. long) breaking forth along the sides of the larger branches, 
or on subglobose galls (1.5-2 cm. in diameter) on the smaller 
branches, applanate, indefinite, usually of considerable size, often 
covering the whole hypertrophied area, sometimes becoming 
patelliform when expanded, chocolate-brown; teliospores 2-celled, 
ellipsoid, 18-28 x 42-61 n, usually slightly narrowed both above 



368 THE FUNGI WHICH CAUSE PLANT DISEASE 

and below, slightly or not constricted at the septum, wall cinnamon 
brown, 1-1.5 n, thick; pores usually 3 in upper cell, 1 apical, 2 
near the septum, in the lower cell 2 pores near the septum. 

and I on apple and mountain ash. 

III. Telia on Juniperus communis and J. sibirica. In Europe. 

The teliospores occur on both twigs and leaves. Marked def- 
ormation is caused by this stage on leaves and petioles. 

G. clavipes C. & P. '°^ (=G. germinale [Schw.] Kern). 

I. ^cia (=Roestelia aurantiaca) on stems and fruits, crowded 
on hypertrophied areas of various size on the twigs and peduncles, 
occupying part or nearly all of the surface of the fruits, cylindric, 
1.5-3 mm. high by 0.3-0.5 mm. in diameter; peridium whitish, 
becoming coarsely lacerate, sometimes to base, erect or spreading; 
peridial cells seen in both face and side views, polygonal-ovate or 
polygonal-oblong in face view, 19-39 x 45-95 /jl, rhomboid in side 
view, 25-40 ju, thick, outer wall moderately thick, 3-5 fx, inner wall 
very thick, 13-23 ix, coarsely verrucose with loosely set, large, 
irregularly branched papillae, side walls verrucose on inner half 
similar to inner wall; seciospores globoid, large, 31-32 x 24-39 fi, 
wall pale yellow, thick, 3-4.5 n, rather coarsely verrucose with 
crowded slightly irregular papillae. 

III. Telia caulicolous, appearing on slight fusiform swellings, 
usually aggregated, roundish, 1-4 mm. across, often confluent, 
hemispheric, 1-3 mm. high, orange-brown; teliospores 2-celled, 
ellipsoid, 18-26 x 35-51 /x, roundish or somewhat acutish above, 
obtuse below, slightly or not constricted at the septum, wall 
yellowish, 1-2 ^t thick, slightly thicker at the apex; pedicles caroti- 
form, 9-19 fx in diameter near the spore; pores one in each cell, 
apical in the upper, near the pedicel in the lower. 

I. iEcia on Amelanchier, Aronia, Crataegus, Cydonia, and 
apple. 

III. Telia on Juniperus communis and J. sibirica. 

G. cornutum (Pers.) Arth. 

A rather uncommon species with I ( = Roestelia cornuta [Pers.] 
Fries) on Sorbus spp. and III on Juniperus communis and 
J. sibirica. Ranging from New York to Wisconsin and northward; 
also in the mountains of Wyoming and Colorado : Europe. Of no 
considerable economic importance in America. 



THE FUNGI WHICH CAUSE PLANT DISEASE 369 

G. eUisii (Berk.) Farl. 

I. ^Ecium unknown. III. Telia on Cupressus thyoides. Prob- 
ably of very small economic importance. 

G. transformans (Ellis) Kern. (=Roestelia transformans 
Ellis). 

I. iEcia on Pyrus arbutifolia, which is of no economic im- 
portance. Confined to a small area from Massachusetts to New 
Jersey. 

III. Telia unknown. 

G. nidus-avis Thax. -'os. 217 

I. iEcia amphigenous, especially fructicolous, cylindric, 2^ mm. 
high by 0.4-6.7 mm. in diameter; peridium soon becoming irregu- 
larly lacerate usually to base, slightly spreading; peridial cells, 
seen in both face and side views, lanceolate in face view, 15-23 x 
55-88 jj,; linear in side view, 14-18 fx, thick, outer wall 1-.5 n 
thick, smooth, inner and side walls 5-7 fx thick, coarsely rugose 
with narrow ridges, with shorter, often roundish papillae inter- 
spersed; seciospores globoid or broadly ellipsoid, 18-23 x 23-28 /x, 
wall cinnamon-brown, rather thick, 2.5-4 fx, very finely verrucose, 
appearing almost smooth when wet. 

III. Telia caulicolous, often dwarfing the young shoots and 
causing birds' nest distortions, or witches' brooms, usually causing 
a reversion of the leaves to the juvenile form, sometimes appearing 
on isolated areas on the larger branches and producing gradual 
enlargements, solitary or rarely confluent, of variable size and 
shape, roundish to oval on the young shoots, 1-2 mm. across, oval 
to nearly elliptic on the woody branches, 1.5-3 mm. wide by 
2-7 mm. long, pulvinate when young, becoming hemispheric, dark 
reddish-brown; teliospores 2-celled, ellipsoid, 16-23 x 39-55 /jl, 
wall pale cinnamon-brown, rather thin, 1-1.5 /x, very slightly 
thicker at apex; pores one in a cell, apical. Mycelium perennial 
in leaves, branches or trunks of Juniperus virginiana very com- 
monly inducing a "bird's nest" distortion. 

I. Mc'ia on Amelanchier and quince. 

III. Telia on Juniperus virginiana. 

G. sabinae (Dicks) Wint. 

O and I (=Roestelia cancellata), on pear in Europe. 

III. Telia on several Junipers. 



370 THE FUNGI WHICH CAUSE PLANT DISEASE 

The telial mycelium is perennial and causes swellings. From 
these in spring ooze the gelatinous, transparent spore-masses. 

The mycelium in Juniperus causes increase in wood-bast and 
rind, thickened twisted tracheids, increase in number and thick- 
ness of the medullary rays. No mycelium is found in the wood 
itself. 

G. biseptatum Ell. 

I. iEcia (=RcesteUa botryapites) hypophyllous, usually in 
groups of 2-8, rarely solitary, borne in gall-like pyriform protuber- 
ances 1-1.5 mm. in diameter by 1.5-3 mm. high, cylindric, 0.5-0.8 
mm. in diameter by 2-4 mm. high; peridium soon becoming finely 
cancellate, not dehiscent at apex; peridial cells cylindric, hyphal- 
like, 9-14 /i in diameter by 145-190 /z long, often irregularly bent, 
outer, inner, and side walls of equal thickness, about 1.5-2 ju, 
whole surface smooth; seciospores globoid, small, 15-17 x 16-22 /x, 
wall dark cinnamon-brown, rather thick, 2.5-3 fx, moderately 
verrucose. 

III. Telia caulicolous, appearing on fusiform swellings, scattered, 
oval or irregular, about 1.5-3 mm. wide by 2-7 mm. long, often 
confluent, hemispheric, chestnut-brown; teliospores 2 to 4-celled, 
13-19 X 35-77 fx, usually rounded above, somewhat narrowed be- 
low, slightly constricted at the septa, wall pale-yellow, 1.1-5 fx 
thick, pores 2 in each cell, near the septa. 

I. iEcia on Amelanchier. 

III. Teha on Chamsecyparis. 

G. nelsoni Arthur. ^Ecia hypophyllous and fructicolous, usually 
in small groups 1-2 mm. across, cylindric, 2-4 mm. high by 0.2- 
0.3 mm. in diameter; peridium whitish, dehiscent at apex and 
also rupturing more or less along the sides; peridial cells seen in 
both face and side view, 18-35 x 75-115 ii, linear rhomboid in side 
view, 16-35 n, thick, outer wall rather thin, 1.5-2 fx, smooth, 
inner and side walls rather thick, 7-12 ju, evenly and densely 
verruculose; seciospores globoid, 19-26 x 21-29 ix, wall chestnut- 
brown, 2-3 fx thick, finely verrucose. 

III. Telia caulicolous, appearing on firm, woody, globose galls 
0.5-5 cm. in diameter, unevenly disposed, densely aggregated or 
often separated by the scars of the sori of previous seasons, ir- 
regularly flattened, about 1-1.5 mm. broad by 1-5 mm. long at the 



THE FUNGI WHICH CAUSE PLANT DISEASE 371 

base by 3-4 mm. high, often confluent, light chestnut-brown; telio- 
spores 2-celled, narrowly ellipsoid, 18-26 x 50-65 /x, narrowed at 
both ends, slightly constricted at the septum; wall pale cinnamon- 
brown, 1-1.5 II thick; pores two in each cell, near the sep- 
tum. 

I. iEcia on Amelanchier, Peraphyllum, quince and pear. 

III. Telia on Juniperus spp. 

Range; Alberta, south to Colorado and Arizona. 

G. japonicum Syd. -^^ 

I. ^Ecia ( = R. koresensis), on Pear. 

III. Telia on Juniperus. 

This form has been imported into America. 

G. torminali-juniperinum (Ed.) Fischer. 

This species has its aecial stage on species of Sorbus and its 
telia on Juniperus in Europe. It is closely related to G. cor- 
nutum of the northern part of our own continent, and of 
Europe. 

G. yamadae Miyabe. Only the aecia of this species have been 
found. It infests the apple and various other sDecies of Malus in 
Japan, 

Uromyces Link (p. 355) 

0. Pycnia spherical with minute ostioles. 

1, ^Ecia with peridia, spores without pores. 

II. Urediniospores generally with many germ pores, unicellular, 
spherical, ellipsoid or variously shaped, usually rough. 

III. Teliospores unicellular, pedicellate, with an apical germ 
pore. 

The unicellular teliospores may be distinguished from uredinio- 
spores by their single apical germ pore, also usually by their 
thicker walls and absence of the roughness so characteristic of 
urediniospores. 

The genus is a verjdarge one, with hundreds of species, which ex- 
hibit hetercecism, autoecism, biologic specialization and the various 
types regarding spore forms that are noted on pages 324-327. 

U. appendiculatus (Pers.) Lev.^^^ 

I. iEciospores angularly globose, whitish, slightly punctulate, 



372 



THE FUNGI WHICH CAUSE PLANT DISEASE 




Leaf Tissue 



17-32 X 14-20 IX. II. Urediniospores pale-brown, aculeolate, 24-33 
X 16-20 M- III. Teliospores elliptical or subglobose, smooth, 

dark-brown, apex much thick- 
ened, with a small, hyaline, wart- 
like papilla, 26-35 x 20-26 ju- 

An autoecious eu-type. On 
Phaseolus, Dolichos and other 
related legumes. 

The sori usually appear late 
in the season on leaves, rarely on 
stems and pods. The mycelium 
is local. Great difference in 
varietal susceptibility is noted. 

U. pisi (Pers.) de B.®' 

I. ( =^cidium cyparissia^). 

Fig. 267. — Diagrammatic section of ure- 7^ . j.j. i xu i 1 

dinium of u. appendicuiatus. After ^^cia scattered over the whole 
Wiietzel. [gg^f surface. Peridia cup-shaped, 

with whitish edges. Spores subglobose or polygonal, orange, 

finely verrucose, 17-26 /x in diameter. 

II. Uredinia roundish, scattered or crowded, cinnamon-brown. 
Spores subglobose or 
elongate, j^ellowish- 
brown, echinulate, 17- 
20 X 20-25 fi. 

III. Telia roundish 
or elliptical, blackish. 
Spores subglobose or 
shortly elliptical, finely 
but closely punctate, 
apex only slightly 
thickened, 20-30 x 17- 
20 {X. Pedicels long, 
colorless, fragile. 

A heteroecious eu- 
type not found in 
America: O and I on Euphorbia. 

II and III on Lathyrus, Pisum, Vicia. 

The secial stage dwarfs the host in which it is perennial. 




• Elpidermis 
' ' of Leaf 



Spores 



- Leaf Ti55ae 
Fig 



Young Spore 



268. — Diagrammatic section of teliospores of 
U. appendicuiatus. After WhetzeL 



THE FUNGI WHICH CAUSE PLANT DISEASE 



373 



U. fabae (Pers.) De B.-*^ This is an autoecious cu-type whicli 
causes a rust of tlie broad bean, vetches, peas. 

U. trifolii (Hed.) Lev.--^"'--^ An autoecious eu-type. 

I. yEcia in circular clusters, on pallid spots. Peridia shortly 
cylindric, flattish, on the stems in elongated groups; edges whit- 
ish, torn. Spores siibglobose or irregular, finely verrucose, pale- 
orange, 14-23 n in diameter. 

II. Uredinia pale-brown, rounded, scattered, surrounded by the 





Fig. 2G9. — L roniyces appen- 
diculatus, teliospore ger- 
minating. After Tulasne. 



Fig. 270. — Uredini- 
ospore and telio- 
spore of Uioniy- 
ces trifolii. Af- 
ter Cobb. 



torn epidermis. Spores round or ovate, with tliree or four equa- 
torial germ pores, echinulate, brown, 20-26 x 18-20 fx. 

III. Telia small, rounded, almost black, long covered by the 
epidermis. Spores globose, elliptical or subpjTiform, with wart- 
like incrassations on their summits, smooth, dark-brown, 22-30 x 
15-20 n. Pedicels long, deciduous. 

Cosmopolitan on white, crimson and alsike clovers. Stages 
O and I are most common on Trifolium repens, least common on 
T. incarnatum. Pycnia appear in early spring or even in winter. 
The seciospores germinate readily in water and give infections which 
give rise to urediniospores in about two weeks. Urecliniospores 
maj'' be produced throughout the summer and may even survive 
the winter. Teliospores are produced in the uredinia or in 
separate sori late in the season. The teliospores by infection 



374 



THE FUNGI WHICH CAUSE PLANT DISEASE 



give rise to the pycnial and secial stages. Considerable distor- 
tion arises in parts affected by either stage. 

U. fallens (Desm.) Kern.^^^ A form on crimson, zig-zag and 
red clover often confused with the last species. 

O and I unknown. 

II. Urediniospores with four to six scattered germ pores. 

III. Teliospores similar to those of U. trifolii. 
U. medicaginis Pass. 

and I. Pycnia and aecia as in U. pisi. 

II. Uredinia chestnut-brown, spores globose to elliptic, 17- 
23 n, light-brown. 




Fig. 271. — Uredo stage of U. betse. After Scribner. 



III. Telia dark-brown, spores ovate-elliptic or pyriform 18-28 x 
14-20. 

A heteroecious eu-type. I, on Euphorbia; in Europe. 

II and III on alfalfa and clovers in Europe and America. 

U. minor Schr. is an autoecious opsis-type, I and III on Trifo- 
lium montanum. 

U. betaB (Pers.) Tul. ' An autoecious eu-type; on members 
of the genus Beta both wild and cultivated. In the United States 
observed only in California. Recorded in Europe, Africa, Australia. 

U. kuhnei Krug. occurs on sugar cane.^^^ 

U. dactylidis Otth. is a heteroecious eu-type; II and III on 
Phleum, I on Ranunculus, in Europe. 

U. poae Rab. is a heteroecious eu-type; I on Ranunculus and 
Ficaria; II and III on Poa. 



THE FUNGI WHICH CAUSE PLANT DISEASE 375 

U. caryophyllinus (Schr.) Wint."''-^^'-' 

I. ^cia on Euphorbia in Europe. 

II. Uredinia sparse, confluent on stems, spores round, elliptic 
or oblong, 40 x 17-28 n, light-brown. 

III. Teliospores globose, irregular or ovoid, apex thickened 23- 
35 X 15-22 mm., pedicel 4-10 ju- 

II and III on cultivated carnations and several other members 
of the genus Dianthus. I on Euphorbia gerardiana. It has been 
known in Europe since 1789 but was not noted in the United States 
until 1890 when it was found by Taft at Lansing, Mich. It soon 
invaded the whole country causing great loss. There is large racial 
difference in host susceptibility. 

The urediniospores germinate readily in water and serve to 
propagate the fungus. Studies of the effects of toxic substances 
upon these have been made by Stevens -^^ and by Stewart.^^'^ The 
aecial stage has recently been recognized by Fischer ^^^ as JE. 
euphorbise-gerardianse. 

Less important species are: U. ervi (Wallr.) Plow, an auta?cious 
eu-type on Vicia in Europe; U. erythronii (D. C.) Pass, an opsis- 
type occasional on cultivated Lilium in Europe. U. ficariae Schw. 
is on Ficaria; IT. pallidus Niess. a lepto-type on Cytisus; U. scil- 
larum (Grev.) Wint. a micro-type on Scilla and Muscari. U. jaf- 
frini Del. is reported on vanilla; -^^ U. colchici Mas. on Colchinum 
speciosum in Europe. 

Puccinia Persoon (p. 355) 

O, I, II, as in Uromyces. 

III. Teliospores separate, pedicellate, produced in flat sori, 
consisting of two superimposed cells each of which is provided 
with a germ pore. The superior cell has its germ pore, as a rule, 
piercing its apex; in the inferior or lower the germ pore is placed 
immediately below the septum. 

Mesospores (p. 327) are not rare. They are merely teliospores 
with the lower cell wanting, and function as teliospores. 

Some one thousand two hundred twenty-six species are enumer- 
ated by Sydow ^^ presenting great diversity in spore relation, 
hetercecism and biologic variation. 



376 



THE FUNGI WHICH CAUSE PLANT DISEASE 



P. cerasi Ces. is a hemi-type on cherries in Southern Europe. 

P. ribis-caricis Kleb. 

I on Ilibes. II and III on Carex. 

Klebahn -^^ differentiates five species of Puccinia on Ribes be- 
longing to the Ribis-Carex group. These are P. pringsheimiana 
(I.=jE. grossularise.) P. ribis-pseudocyperi, P. ribis nigri-acutse, 
P. ribis nigri-paniculatae and P. magnusii. 

P. asparagi D. C.^^^-^^o 

I. Peridia in elongated patches upon the stems and larger 
branches, short, edges erect, toothed. Spores orange-yellow, 
round, very finely echinulate, 15-26 /x in 
diameter. 

II. Uredinia browTi, flat, small, long 
covered by the epidermis. Spores irregu- 
larly round or oval, clear-broA\Ti, echinu- 
late.- 18-25 X 20-30 IX. 

III. Telia black-brown, compact, pul- 
vinate, elongate or rounded, scattered. 
Spores oblong or clavate, base rounded, 
apex thickened, darker, central con- 
striction slight or absent, deep chest- 
nut-brown, 35-50 X 15-25 ju- Pedicels 
persistent, colorless or brownish, as long 
as or longer than the spores. 

An autoecious eu-type on Asparagus, 
cultivated and wild. The fungus has 
been known in Europe since 1805 but did not attract attention 
in the United States until 1896 in New Jersey ^^^ when it began 
its devastating westward migration ^^^ across the country reaching 
California in 1900 or 1901. 

The secial stage appears in early spring; the seciospores may 
germinate at once or if dry remain viable for several weeks, 
their germ tubes penetrating the host in most cases stomatally. 
The uredinia appear in early summer soon after or with the secial 
stage and, wind borne, distribute the fungus. The uredinio- 
spores remain viable a few months when dry. The telial stage 
appears late in the season and germinates only after hibernation. 

Unicellular spores, mesospores, are sometimes met. 




Fig. 272. — Section through 
black rust pustule, show- 
ing teliospores of P. as- 
paragi. After Smith. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



377 




Fiu. 273. 



-Cross-section of aecia of P. asparagi. 
After Smith. 



P. buUata (Pers.) Schr. is a l^rachy-puccinia which is autcecious 
on celery, parsley, cHU and other umbellifers. 

P. apii (Wallr.) Cda. also occurs in its uredinial and telial stages 
on celery. 

P. castagnei Thiim is recorded for celery in France. 

P. allii (D. C.) Ilud. is a hemi-type on cultivated onions. 

P. porri Sow. is an autcecious rust which is sometimes de- 
structive to onions in y^ n ^n Ci 
Europe. -><^=#=^^ mocyRX^Br 

P. endiviae Pass."^- 
occurs on endive in 
Italy and America. 

P. phragmitis 
Schum.2^.^-244 

I {=M, rubellum). 
Peridia on circular 
red spots 0.5-1.5 cm. 
in diameter, shallow, 
edges white, torn. Spores white, subglobose, echinulate, 15-16 n 
in diameter. 

II. Uredinia rather large, dark brown, elliptical, pulverulent, 
without paraphyses. Spores ovate or elliptical, echinulate, brown, 
25-35 X 15-23 n. 

III. Telia large, long, sooty black, thick, often confluent. 
Spores elliptical, rounded at both ends, markedly constricted in 
the middle, dark blackish-brown, smooth, 45-65 x 16-25 fx. Pedi- 
cels very long, 150-200 x 5-8 ijl, yellowish, firmly attached. 

Hetercecious; I on Rumex and rhubarb, II and III on Phrag- 
mitis. Found only rarely in America,^'*^' ^^* except in the middle 
west. 

P. cyani (Schl.) Pass, is on cultivated Centaurea. 

P. tragopogonis (Pers.) Cda. 

I. ^cia on the whole plant — leaves, stems, bracts, receptacles 
■ — shortly cylindrical, at first mammseform, peridia with whitish, 
torn edges. Spores rounded, verrucose, orange-yellow, 18-27 fx, 
sometimes as much as 35 fx. long. Mycelium diffused throughout 
the host-plant. 

III. Telia brown, few, small, scattered, elliptical or elongate, 



378 



THE FUNGI WHICH CAUSE PLANT DISEASE 



long covered by the epidermis. Spores broadly oval, often 
almost globose, slightly constricted, apex not thickened, thickly 
verrucose, brown, 26-48 x 30-35 fx. Pedicels short, colorless, 
deciduous. Mycelium localized. 

An opsis-type on cultivated Tragopogon. Urediniospores are 
unknown. The teliospores are often unicellular and are very 
variable. 

P. taraxaci Plow, is common on dandelion. P. cichorii Pass, is a 
hemi-type on Cichorium. P. isiacae on Phragmitis is thought to be 




Fig. 274. — P. graminis, telium and germinating 
teliospore. After Carleton. 

the telial stage of JE. brassicae on cabbage. ^'^^ P. fagopyri Barcl. 
is found on buckwheat. 
P. menthae Pers. ^'^ 

I. iEcia with peridia immersed, flat, opening irregularly, edges 
torn; principally on the stems, which are much swollen, more 
rarely on concave spots on the leaves. Spores subglobose or 
polygonal, coarsely granular, pale-yellowish, 17-26 x 26-35 m- 

II. Uredinia small, roundish, soon pulverulent and confluent, 
cinnamon-brown. Spores irregularly rounded or ovate, echinu- 
late, pale-brown, 17-28 x 14-19 fi. 

III. Telia black-brown, roundish, pulverulent. Spores ellip- 
tical, oval, or subglobose, central constriction slight or absent, 
apex with a hyaline or pale-brown papilla, verrucose, deep-brown, 
26-35 X 19-23 /x. Pedicels long, delicate, colorless. 

An autoecious eu-type on many mints. 



THE FUNGI WHICH CAUSE PLANT DISEASE 379 

•r» • • T. *8. 166-182, 246. 306, 322 

P. graminis Pers. ' 

I {=M. berberidis). Spots generally circular, thick, swollen, 
reddish above, yellow below. Peridia cylindrical, with whitish 
torn edges. Spores subglobose, smooth, orange-yellow, 15-25 m- 

II. Uredinia orange-red, linear, but often confluent, forming 
very long lines on the stems and sheaths, pulverulent. Spores 
elliptical, ovate, or pyriform, with four very marked, nearly 
equatorial germ pores, echinulate, orange-yellow, 25-38 x 15-20 m- 

III. Telial persistent, naked, linear, generally forming lines on 
the sheaths and stems, often confluent. Spores fusiform or clavate, 
constricted in the middle, generally attenuated below, apex much 
thickened (9-10 n), rounded or pointed, smooth, chestnut-brown, 
35-65 X 15-20 n. Pedicels long, persistent, yellowish-brown. 

O and I on Berberis and Mahonia. 

II and III on Avena, Hordeum, Secale, Triticum and nearly 
fifty other grasses. Of great importance on wheat in the Great 
Plains and along the Ohio. 

This fungus was the subject of the classic researches of de 
Bary ^^^ begun in 1865 and has since repeatedly served as the basis 
of fundamental investigations in parasitism, cytology and biologic 
specialization. That the barberry seciospores can bring about 
cereal infection seems to have been shown as early as 1816. ^^^ 
Inoculations in the reverse order were made in 1865. ^^^ Extensive 
studies by Eriksson ^^"^ are interpreted by him to show that what 
was formerly regarded as one species must be separated on bio- 
logic grounds into several races which he finally erects as species, 
though others do not agree that their rank should be specific. 
These are: P. graminis secalis. P. graminis avense. P. graminis 
tritici. P. graminis airse. P. graminis pose. P. phlei-pratensis. 

These words from Butler and Hayman ^^° show the complexity 
of the status of these biologic forms. 

"Of late years it has become more and more established that 
parasitic fungi, which are capable like these rusts of living on 
several hosts, tend to develop 'races' on their different host- 
species, marked off from each other by definite characters. Some- 
times the characters are such as are capable of being detected 
microscopically. Usually, however, the fungi are, to all appear- 
ance, identical, and differences only appear when their manner of 



380 THE FUNGI WHICH CAUSE PLANT DISElASE 

life is carefully studied. The chief of these is the incapacity of a 
race to attack the host-plants of another race. Such forms as 
are thus outwardly identical but which show a constant difference 
in their mode of life are known as "biological" species or. ksformoe 
speciales. - 

"A speciahzed form is considered to be 'sharply fixed' or 'not 
sharply fixed' according as it is wholly incapable, or sometimes 
capable, of attacking the host-plants of the other specialized forms 
of the same fungus. Thus the P. graminis of wheat (P. graminis 
f. sp. Tritici) is not sharply fixed, for it can attack barley, rye, 
&c., sometimes. The P. graminis found on grasses of the genus 
Agrostis (P. graminis f. sp. Agrostis) is sharply fixed, for it attacks 
this genus only and does not pass to the other grasses on which 
it has been tried. 

"But even the not sharply fixed forms, such as the P. graminis 
of wheat, may be entirely incapable of attacking some of the 
species which bear other forms of the same fungus. In other 
words a form may be not sharply fixed in regard to some host- 
plants and sharply fixed in regard to others. A striking instance 
of this occurs in India. P. graminis can be divided amongst others 
into races on wheat (/. sp. Tritici), rye and barley (/. sp. Secalis), 
and oats (/. sp. Avena). The/, sp. Tritici can attack barley some- 
times, and did so in four out of sixteen of our inoculations, but it 
does not, in India at least, attack oats. Hence it is sharply fixed 
in regard to oats and not sharply fixed in regard to barley. The 
/. sp. Secalis on barley also does not pass to oats, but infected 
wheat doubtfully in two out of sixteen inoculations. These two 
forms are common in India, and the practical bearing of their 
not passing to oats is considerable, for the /. sp. Avenos has not 
yet been observed in this country." 

The mycelium branches intercellularly and bears small haus- 
toria which penetrate the cells. In the barberry it is local. The 
epiphyllous pycnia appear first followed soon by the mainly 
hypophyllous secia. The flask-shaped pycnia at maturity bear 
numerous pycniospores and exserted paraphyses. Their hyphse 
are orange-tinted, due to a coloring matter in the protoplasm or 
later in the cell walls. 

The secium originates in the lower region of the mesophyll 



THE FUNGI WHICH CAUSE PLANT DISEASE 381 

from a hyphal weft. The fertile branches give rise to chains of 
spores every alternate cell of which atrophies. The outer row of 
sporophores and potential spores remains sterile to form the 
peridium. When young the secium is immersed and globular, 
at maturity erumpent and forms an open cup. These spores 
germinate by a tube capable upon proper hosts of stomatal infec- 
tion and following this of producing the uredinium. 

Urediniospores are produced throughout the season even through 
the winter under proper climatic conditions. They also remain 
viable for weeks ^'^^' ^'"^ and doubtless serve hibernation purposes. ^"^ 

Teliospores arise later in the season in the uredinia or in 
separate teUa. Unicellular teliospores, mesospores, are oc- 
casionally seen. Tehospores germinate best after normal out- 
door hibernation, producing the typical 4-celled promycelium, 
long sterigmata and solitary basidiospores. If under water the 
usual promycelium becomes abnormal and resembles a germ 
tube.i^"' 1'^ 

The aecial stage may not occur under certain climatic conditions, 
and the uredinia alone perpetuate the fungus. -^^' -^"' ^■'^' ^"^ It 
therefore follows that eradication of the barberry as was at- 
tempted by legislative enactment in 1660 in Europe and in 1728 
and 1755 in Connecticut and Massachusetts "^^ does not extermi- 
nate the rust ^^* (see also ^^'^' ~^). 

Basidiospores were shown by De Bary, ^^^ confirmed by Ward ^^^ 
and Eriksson, to be incapable of infecting wheat leaves. Suf- 
ficient such attempts have, however, not been made on young 
tissue. ^^° 

Jaczewski ^^^ succeeded in securing germination of pycniospores 
but the resulting mycelium soon died and infection was not at- 
tained. The same author holds that seciospores may remain 
viable about a month, the urediniospores a much shorter time. 
Still hibernation by urediniospores is possible where climatic rela- 
tions allow the formation of new uredinia during the winter. 

P. rubigo-vera (D. C.) Wint.^^^- '''' '^^^ ''' ' 

I{=M. asperifohum, Pers). Spots large, generally circular, dis- 
colored, generally crowded. Peridia flat, broad, with torn white 
edges. Spores subglobose, verrucose, orange-yellow, 20-25 n. 

II. Uredinia oblong or linear, scattered, yellow, pulverulent. 



382 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Spores mostly round or ovate, echinulate, with three or four germ 
pores, yellow, 20-30 x 17-24 m- 

III. Telia small, oval, or linear, black, covered by epidermis, 
surrounded by a thick bed of brown paraphyses. Spores ob- 
long or elongate, cuneiform, slightly constricted, the lower cell 
generally attenuated, apex thickened, truncate or often obliquely 
conical. Spores smooth, brown, variable in size, 40-60 x 15-20 /x- 
Pedicels short. 

Heteroecious ; and I on Boraginacese. 

II and III on rye. The teliospores germinate as soon as mature. 




Fig. 275. — P. rubigo-vera, section of uredinium. 
After Bolley. 

P. triticina Erik, is the most common and widely distributed 
of all rusts of the United States and is a serious wheat pest in 
India. ^^° It ordinarily shows only the uredinial stage. The telio- 
spores germinate the following spring after a resting period. 

Coextensive with wheat culture.^''^ Epidemics are frequent. 

Bolley ^' ^' ^^ (see also ^*'^) has shown it capable of hibernation by 
urediniospores and by live winter mycelium and it has further been 
shown that the spores themselves can survive freezing in ice. The 
secial stage can be entirely omitted. 

This species is combined with P. triticina by Carleton ^^^ and 
treated as two races. The name P. dispersa is also used to 
cover the same two species. P. rubigo-vera tritici on wheat and 
P. rubigo-vera secalis on rye. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



383 



The secial stage of the former of these is not known. Its uredinia 
survive the severest winters even so far north as the Dakotas. 
P. coronata Cda.i^^, 248. soe 

I {=JE. rhamni). Peridia often on very large orange swelhngs, 
causing great distortions on the leaves and peduncles, cylindrical, 
with whitish torn edges. Spores subglobose, very finely verrucose, 
orange-yellow, 15-25 x 12-18 m- 

II. Uredinia orange, pulverulent, elongated or linear, often con- 
fluent. Spores globose or ovate, with three or four germ pores, 
echinulate, orange-yellow, 20-28 x 15-20 m- 

III. Telia persistent, black, linear, often confluent, long 
covered by the epidermis. Spores subcylindrical or cuneiform, 
attenuated below, constriction slight or absent, apex truncate, 




Fig. 276. — P. coronata, various teliospore forms. After Bolley. 

somewhat thickened, with six or seven curved blunt processes, 
brown, 40-60 x 12-20 m- Pedicels short, thick. 

Heteroecious; I, on Rhamnus frangula. 

II and III on various grasses but not on oats. 

From this form as earlier understood Klebahn has separated 
P. coronifera Kleb. on evidence derived from inoculations, and 
made the latter to include these forms with the aecial stage on 
Rhamnus cathartica and the uredinial and telial stages on Avena, 
Lolium, Festuca, Holchus, Alopecurus and Glyceria. P. coronifera 
has been still further divided by Eriksson into eight biologic forms 
and P. coronata into three such forms.^"'^ 

P. glumarum (Schm.) Er. & Hu.^^^' -^'^ is widely distributed on 
wheat, rye, barley and a few other grasses in India and Europe 
but is not known in America.^''^ Its secia are not known. By 
some this is regarded as a race of P. rubigo-vera. Both 
uredinia and teliospores have been reported in the pericarp of 
grains.^® 



384 



THE FUNGI WHICH CAUSE PLANT DISEASE 



P. simplex (Korn.) Er. & He. 

I. Unknown. 

II and III on barley in Europe and seemingly of recent intro- 
duction into the United States. ^"^ 

One of the least important of the grain rusts. Mesospores are 
common. 

P, sorghi Schw.260 

I {=M. oxalidis). Peridia hypophyllous, rarely amphigenous, 
crowded, concentric, epispore smooth, 24-28 /z. 

II. Uredinia amphigenous, numerous, often confluent; spores 
globose to ovate, 23-30 x 22-26 mm., slightly verrucose. 







Fig. 277. — Puccinia sorghi. After Scribner. 



III. Telia amphigenous, black. Spores ovate-oblong or clavate- 
obtuse, constricted. Epispore thick, 28-45 x 12-17 n, smooth, 
pedicel long, 5 n, persistent. 

Heteroecious. and I on Oxahs. II and III on Zea. Of little 
economic importance. 

The relation of the secial stage was demonstrated by Arthur; -*"' 
it is believed, however, that hibernation is largely by the uredinio- 
spores. 

P. purpurea C. Amphigenous, spot purplish, sori irregular, 
dark-brown. 

II. Urediniospores ovate, 35 x 25-30 m, smooth, brown. 

III. Teliospores elongate, ovate, brown, long-pedicellate, 40-45 
X 22-25 M- On Sorghum in Southern United States and West 
Indies. 



THE P^UNGI WHICH CAUSE PLANT DISEASE 



385 



P. phlei-pratensis E. & H.^^^-^ei- ''o^-^o^ 

I. ^Ecia probably on Berberis, but rarely formed. 

IL Uredinia 1-2 mm. long on leaves and stems, confluent in 
lines 10 mm. or more long, yellow-brown; spores oblong, pyriform, 
spiny, 18-27 x 15-19 /z. Mycelium perennial. 

III. Telia in leaves, sheaths and stems, 2-5 mm. long or 
more, confluent, narrow, dark-brown to black, open or partly 




Fiu. 278. — P. malvacearum. After Holway. 

closed. Spores fusiform or club-shaped, medially constricted, 
chestnut-brown, apically thickened, 38-42 x 14-16 m- 

II and III on timothy grass. 

This species is closely related to P. graminis and probably a deri- 
vate from it, but it does not seem capable of infecting the bar- 
berry under ordinary conditions."^^' -*^ 

Inoculation experiments with timothy rust at Washington, D. C, 
show that it can be transferred easily to various grasses. Similar 
results have been obtained by Eriksson in Europe. It is not a 
well fixed species and by using bridging hosts it can be made to 



386 



THE FUNGI WHICH CAUSE PLANT DISEASE 



transfer to various cereals which it will not attack directly. That 
such transfers take place in nature to some extent is probable.^°^ 

P. poarum Niess occurs on bluegrass. 

P. malvacearum Mont.'''^'^^ 

III. Telia grayish-brown, compact, round, pulvinate, elon- 
gate on the stems, scattered, seldom confluent, pale reddish- 
brown. Spores fusiform, attenuated at both extremities, apex 
sometimes rounded, constriction slight or absent, apical thickening 
slight, smooth, yellow-brown, 35-75 x 15-25 /x. Pedicels firm, 
long, sometimes measuring 120 fx. 

A lepto-puccinia on three species of Althea, seven of Malva, two 
of Malope; particularly serious on the hollyhock. A native of 
Chili, it was first known as a pest in Australia; soon afterward in 
Europe. It seems to have entered the United States sometime 
prior to 1886 and is now almost universal. The tehospores ger- 
minate immediately in suitable environment, mainly from the 
apical cell, or may remain alive over winter and originate the 
spring infection. The mycelium also hibernates in young leaves. 
Mesospores are common. 3 to 4-celled teliospores are also met. 
P. heterogena Lag. is also described on 
hollyhock from^*^^ South America. 
P. chrysanthemi Roze.^^e-ses 

II. Uredinia chocolate-brown, single or in 
circular groups, hypophyllous, rarely epiphyl- 
lous. Spores spherical to pyriform. Mem- 
brane spiny and with three germ pores, 17-27 x 
24-32 /x. 

III. Telia dark-brown hypophyllous. Telio- 
spores rarely in uredinia, dark, obtuse, apex 
thickened, membrane thick, finely spiny, 20- 
25 X 35-43 fjL. Pedicel 1-13^ times the spore 
length. 

On cultivated Chrysanthemum. Occasion- 
ally urediniospores like the other uredinio- 
spores in all other respects but 2-celled are 
found; a habit unique with this rust. In many places uredinio- 
spores may be produced continuously and teliospores be but rarely 
seen, thus in America only urediniospores have been found. It was 




Fig. 279.— p. helianthi, 
uredinio- and telio- 
spores. After Cobb. 



THE FUNGI WHICH CAUSE PLANT DISEASE 387 

first seen in America in 1896 (Mass.) and soon spread over the 
country. Numerous inoculation trials go to show that it is inde- 
pendent of the other rusts common on nearly related Compositse.^^^ 

P. arenariae Wint.^°^ 

III. Telia compact, pulvinate, roundish, scattered, often cir- 
cinate. Spores broadly fusiform or pyriform, summits pointed or 
rounded, often thickened, base rounded or attenuated, slightly 
constricted, smooth, pale yellowish-brown, 30-50 x 10-20 ii. 
Pedicels hyaline, colorless, as long as the spores. 

A lepto-puccinia common on Dianthus. 

P. helianthi Schw. 

0. Pycnia clustered. 

1. Mcia in orbicular spots; peridial margins pale, torn; spores 
orange, rarely whitish. 

II. Uredinia minute, round, chestnut-brown, spores globose to 
ovate, 22-26 x 17-22 n, minutely spiny. 

III. Telia round, dark-brown to black; spores rounded at base, 
slightly constricted, 38-50 x 20-27 n, smooth; pedicel hyaline, 
equal to or longer than the spores. 

Autoecious on numerous species of Helianthus, probably divis- 
ible into numerous biologic forms. Imported from America to 
Europe. 

Arthur ^°^ used fifteen species of Helianthus on which to sow the 
teliospores of Puccinia helianthi produced on three species. The 
results are given in table I on page 388. 

In the course of three years' work with this species sixty sowings 
were made. 

"Looking over the table it will be seen that each set of spores 
grew upon the species of host from which derived, but not upon 
the other two species, except that spores from H. loetiflorus sown 
on H. mollis gave a tardy showing of pycnia, without further 
development. Also each set of spores grew luxuriantly upon H. an- 
nuus, and each made a feeble growth upon H. tomentosus, but on 
all other species they either failed to infect or made a feeble growth, 
with the single exception that spores from H. Icetiflorus grew well 
on H. scaberrimus." P. Helianthi thus affords an example of a 
single species having many races, for which H. annuus acts as a 
bridging host. 



388 THE FUNGI WHICH CAUSE PLANT DISEASE 







Table 


I 








RESULTS OF INOCULATIONS 


OF 


HELIANTHUS 


RUST * 








Teliospores taken from 






H. mollis 




H. grosse- 
serratus 


H. la^ti- 
florus 


1. 


H. annuus 


+ 




+ 


+ 


2. 


H. decapetalus 


a 







a 


3. 


H. divaricatus 


a 




a 


— 


4. 


H. grosse-serratus 







+ 





5. 


H. hirsutus 


— 










G. 


H. kellermani 


o 




a 


— 


7. 


H. liBtiflorus 










+ 


8. 


H. maximiliani 


o 







a 


9. 


H. mollis 


+ 




O 


— 


10. 


H. occidentalis 


— 







— 


11. 


H. orgyalis 













12. 


H. scaberrimus 










+ 


13. 


H. strumosus 


— 










14. 


H. tomentosus 


— 




— 


— 


15. 


H. tuberosus 







O 


O 



+ Abundant infection. — Infection, but slow growth and few or no 
secia formed, o No infection, a Not sown. 

P. violae (Schum) D. C.^^a 

I. JEcisi on the leaves in circular concave patches, often caus- 
ing much distortion on the stems, flat with white torn edges. 
Spores subglobose, finely verrucose, orange-yellow, 16-24 x 10-18 fx. 

II. Uredinia brown, small, roundish, scattered, soon naked. 
Spores roundish or elliptical, brown, echinulate, 20-26 n in diameter. 

III. Teha black, roundish, small, pulverulent. Spores ellip- 
tical or oblong, slightly attenuated at the base, with an apical 
thickening, constriction almost absent, brown, 20-35 x 15-20 /x. 
Pedicels long, deciduous. 

An autoecious eu-type on many species of Viola, throughout the 
world. Of little economic import. 
P. convallariae-digraphidis (Soph.) Kleb. is heteroecious; 
I on Convallaria majalis. Ill on Phalaris. 
* Adapted from Arthur. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



389 



P. gentianae Strauss is a eu-puccinia on many species of cul- 
tivated gentians. P. gladioli Cast occurs on gladiolus. P. gran- 
ulans Kale. & Cke. is on cultivated Pelargoniums in France;-™ 
P. tulipae Schr. on tulips; P. scillae Lk. on Scilla; P. schroeteri 
Pass, on Narcissus in Europe. P. pazschkei Diet, is a lepto- 
puccinia on cultivated saxifrages in Europe. P. horiana Hen. 




Fia. 280.— P. dianthi. Aftor Holway. 



is destructive on Chrysanthemums in Japan.-^^ P. iridis (D. C.) 
Duby, a hemi-puccinia, is found on many species of Iris. 
P. cannae Hen. in its uredinial stage is destructive to Cannas 
in the West Indies. P. persistens Plow, is heteropcious. I on 
Thalictrum. II and III on Agropyron. P. asteris Duby. is a 
very common lepto-puccinia on various asters. P. anemones- 
virginianae Schw. is a lepto-puccinia common on anemone. 

Key to Uredinales Imperfect! (p. 335) 

Spores catenulate 

Peridium absent 1. Caeoma, p. 390. 

Peridium present 

Toothed, body cup-shaped 2. jEcidium, p. 390. 

Fimbriate, body elongate 3. Roestelia, p. 391. 

Irregularly split 4. Peridermium, p. 390. 

Spores not catenulate 5. Uredo, p. 392. 



390 THE FUNGI WHICH CAUSE PLANT DISEASE 



-^cidium Persoon (p. 389) 

Spores surrounded by a cup-shaped peridium; produced catenu- 
late in basipetal series. Germination as in Uredo. 

The species are very numerous and belong in the main to Puc- 
cinia and Uromyces. Most of the forms of economic interest are 
found under these genera. A few others of occasional economic 
bearing whose telial stage has not yet been recognized are given 
below. 

A. brassicae Mont, on Brassica is perhaps identical with Puccinia 
isiacse. See p. 378. A. tuberculatum E. & K.^^^ is reported as 
destructive on the poppy mallow. A. pelargonii Thiim. occurs 
on geraniums; 2^° A. otogense Lindsay on Clematis.^" A. cin- 
namomi Rac. is serious on the cinnamon tree in Java. 

Caeoma Link (p. 389) 

Sori without a peridium, accompanied by pycnia, with or with- 
out paraphyses, produced in chains. Germination as in Uredo. 

The forms are mostly stages of Melampsora, Phragmidium or 
their kin. Those of economic interest are found under Gymno- 
conia and Melampsora. 

Peridermium Leviell6 (p. 389) 

Pycnia truncate-conic. 

Peridia caulicolous or foliicolous, erumpent, saccate to tubular, 
lacerate-dehiscent, spores catenulate or at maturity appearing 
solitary, globose to elliptic or oblong, polyhedral by pressure, 
yellowish-brown. Epispore always verrucose-reticulate. 

The secial stages of Coleosporium, Cronartium, Pucciniastrum, 
Melampsorella and Chrysomjoca. 

The peridia usually extend conspicuously above the host sur- 
face, and rupture irregularly by weathering. 

All of the species grow on the Coniferse, most of them on Pinus 
on both leaves, branches and bark. On the leaves the aecia are 
much of the type shown in Fig. 256. When on the woody parts 
great distortion may be caused by the perennial fungus and much 
injury result to the wood (see Cronartium quercus, p. 352). 

The mycelium may live intercellularly in rind, bast and wood 



jr^- 



THE FUNGI WHICH CAUSE PLANT DISEASE 



391 



of pine and continues to extend for years causing swellings of 
twigs. Pycnia are either subcuticular or subepidermal and the 
pycniospores often issue in a sweetish liquid. ^Ecia occur as 
wrinkled sacs emerging from the bark of the swollen places and 
bear spores perennially. 

A key to some thirty species is given by Arthur & Kern.^^^ 
So far as it relates to the distribution of the Peridermiums to 
their telial genera it is as follows : 

Key to Species of Peridermium 

Pycnia subcuticular 

iEcia cylindrical Pucciniastrum. 

iEcia tongue-shaped Melampsorella, Melamp- 

soridium. 
Pycnia subepidermal 

^cial peridia one cell thick 

On Pinus Coleosporium. 

On Picea Melampsoropsis. 

On Abies Uredinopsis. 

Pycnia subcorticular 
JEcial peridia more than one cell thick . . . Cronartium. 

Such forms as are of economic interest and of which the telial 
stage is known are discussed under Coleosporium, Cronartium, 
Melampsorella, Melampsoropsis and Pucciniastrum. 

Several other forms are found on pine, spruce and Tsuga. 




Roestelia Rebentisch (p. 389) 

0. Pycnia spherical or cup- 
formed. 

1. ^cia with strongly de- 
veloped thick-walled peri- 
dium, flask-shaped or cylin- Fig. 281 
dric; spores globose, 1-celled, 
brown to yellow, catenulate, with several evident germ pores. 

The forms are the acial stages of Gymnosporangiums and 
occur mostly on Rosaceous hosts. The economic forms will be 
found under Gymnosporangium. 



^^ 



R. pyrata, cups showing peridial 
cells. After King. 



392 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Uredo Persoon (p. 389) 
Spores produced singly on the terminal ends of mycelial hyphse. 
Germination by a germ-tube which does not produce basidio- 
spores, but enters the host-plant through 
the stomata. 

These forms are in the main discussed 
under their telial genera. 

U. orchidis Wint. and U. satyrii Mass. 
are in the leaves of cultivated orchids. 
U. tropaeoli Desm. is found on Tropseolum ; 
U. arachidis Lag. the peanut ; ^-^ U. auran- 
tiaca Mont, on Oncidium.^^° U. au- 
tumnalis Diet, on Chrysanthemums in 
Japan ^^^ and U. kuhnii (Kr.) Nak. on 
sugar cane in Java. 

The Auriculariales (p. 323) 

Mycelium septate, forming a gelatinous, 
irregular and expanded or capitate sporo- 
carp; hymenium variable, densely beset 
Fig. 282.— Various hasidia of with basidia, on each segment of which is 
the lower basidiomycetes, bornc a loug sterigma, with its single 

1, auriculanas; 2, tremellas 007 o 

with longitudinal divisions; spore. 

3, dacryomycetes with un- rr-ii » * 1 • 1 j 1 

divided forked basidium. ihe Auriculariales are mostly sapro- 

phytic and of little economic importance. 
They embrace some fifty species in two families and are chiefly 
of interest on account of the form of their basidia Fig. 282, which 
shows relationship both to the Ustilaginales and to the orders to 
follow. 

Key to Families op Auriculariales 

Hymenium gymnocarpous 1. Auriculariaceae, p. 392. 

Hymenium angiocarpous 2. Pilacraceae. 

Auriculariaceae 

Key to Tribes or Genera of Auriculariaceae 
Sporocarp arising from a ton-like base of 

mycelial threads I. Stypinelleae. 




THE FUNGI WHICH CAUSE PLANT DISEASE 393 

Basidia free on the end of the hyplue 

without saccate cell 1. Stypinella, p. 393. 

Basidia subtended by a saccate cell 2. Saccoblastia. 

Sporocarps crustaceous II. Platygloeeae. 

Sporocarps gelatinous, auriform or caj)- 

shaped III. Auricularieae, p. 393. 

In tribe III, AuriculariesD, there is a single genus, Auricularia. 

Cap more or less cup-shaped or ear-like, jelly-like ])ut firm when 
wet, horny when dry, the hymenium often veined or folded, but 
without teeth. The name refers to the cup-like form. 

A. auricula- judiae (L.) Schr. is a very common saprophyte which 
is occasionally parasitic on elder, elm, and mulberry in Europe. 

In tribe I, few cases of parasitism of any importance are reported. 

Stypinella mompa (Tan.) Lin. is found on the roots of mulberry 
in Japan. 

Eubasidii (p. 299) 

The Eubasidii represent the higher development of the basidia- 
fungi and contain the majority of the species. The basidia, 
the typical club-shaped undivided stalks, bear usually four, 
sometimes two, six, or eight unicellular spores on a like num- 
ber of sterigmata and are mostly arranged in hymenia. There 
is great diversity in the form and size of the sporophore from 
an almost unorganized mycelial microscopic weft to the large 
complex structures of the toad stools and puff balls. Conidia 
and chlamydospores while occasionally present are much less 
common than in the preceding groups or orders. 

The cells of the sporophore in many forms investigated are 
binucleate ; ^^ in other forms they arc multinucleate. 

The origin of the binucleate condition often antedates the for- 
mation of the sporophore and may occur far back in the mycelium, 
perhaps as far back as the germinating basidiospore itself.^^' ^^' ^^ 
In the basidial layer, hov\^ever, even of those forms with multi- 
nucleate vegetative cells, the nuclei are reduced to two so that 
the general statement is permissible that in the hymenial layer 
of the Basidiomycetes the cells are binucleate. From such cells 
two nuclei wander into the basidium primordium where they 
fuse to one, reducing this cell to a uninucleate condition. This 



394 



THE FUNGI WHICH CAUSE PLANT DISEASE 



nucleus by two mitoses gives rise to four nuclei which wander 
through the sterigmata into the spores and constitute the four 
basidiospore nuclei. 

The significance of this phenomenon of fusion in the basidium 
followed by division, which is wide spread and apparently the 




H 



li 




L 



>t 



>>■ 






.\' 



o 





-1 --*i 


(- ) 


I 


\ 1 

o 








'^^Ci^, 



Fig. 283. — Stages in the development of the basidium (Agaricus) ; original 
binucleate condition, followed (E-F) by fusion, and subsequent mitosis N-R, 
resulting in four spore nuclei. After Wager. 

dominant typical phenomenon among the Basidiomycetes includ- 
ing both high forms, Agarics, ^^ and low forms, Dacryomycetes,^^ 
the Uredinales ^^^' ^^' ^^^' ^^^' ^^^ and even the Gasteromycetes 
(Maire),^^^ is much debated. By some it is regarded as a very 
much modified type of fertilization, a view to which support is 
lent by the fact that in some of these fungi, perhaps all, the 
nuclei multiply by a process of conjugate division. Thus the two 
nuclei found in the yoimg basidium, although belonging to the 
same cell may in ancestry be very distantly related. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



395 



Key to Orders of Eubasidii 



Gelatinous fungi with forked basidia 

Basidia clavate, undivided 

Hymenium without stroma, parasites, 

basidia free, strict 

Stroma usually well developed, fleshy, 
coriaceous, leathery or woody 
Spores arising from basidia which form 
a distinct membranous hymenium 
which is naked at maturity, and 
frequently covers the surface of 
gills, pores or spines (Hymenomy- 

cetes) 

Spores arising from basidia enclosed in a 
definite peridium (Gasteromycetes.) 
Spores borne in a more or less deli- 
quescent gleba which is at first 
enclosed in a peridium, but is at 

maturity elevated on stipe 

Spores remaining within the peridium 
until maturity 
Basidia united into a hymenium 
which lines the walls of irreg- 
ular cavities 
Hymenial cavities remaining 
together in the peridium, 
their boundaries mostly 
disappearing at maturity 
Fleshy until the maturity of 
the spores, capillitium 

none 

Fleshy when young, at matu- 
rity filled with dust-like 
spore-masses mixed with 
capillitium (puff balls) . . 
Hymenial cavities separating at 
maturity from the cup-like 
peridium (bird-nest fungi) . 
Basidia uniformly distributed 
through the peridium or 
forming skein-like masses . . . 



1. Dacryomycetales. 



2. Exobasidiales, p. 396. 



3. Agaricales, p. 398. 



4. Phallales, p. 462. 



5. Hymenogastrales. 



6. Lycoperdales, p. 464. 



7. Nidulariales. 



i. Sclerodermatales. 



396 THE FUNGI WHICH CAUSE PLANT DISEASE 

The Dacryomycetales include forms with a gelatinous sporo- 
phore. They are mostly small, inconspicuous saprophytes, common 
on decaying wood, leaves, etc. The Hymenogastrales are puff-ball 
forms, and are very numerous and of very diverse structure. None 
have been reported as parasitic. The Nidulariales is a small order 
comprising the curious bird-nest fungi, all saprophytes. The 
Sclerodermatales are thick-skinned puff balls, mostly subter- 
ranean, and not known to be parasitic. 

Exobasidiales (p. 395) 

Strictly parasitic, the mycelium penetrating the host and usually 
causing marked hypertrophy; hymenium unaccompanied by fleshy 
sporocarp, consisting only of the closely-crowded, clavate basidia 
which break through the epidermis of the host. 

The basidia bear four, rarely five or six sterigmata and spores. 
The spores are mostly curved. Conidia are also found in some 
species. . The basidiospores germinate with a germ tube which pro- 
duces fine sterigmata and secondary spores capable of budding. 
The hymenial cells are binucleate, the two nuclei of the basidial cell 
fusing into one basidium-nucleus. This divides mitotically giv- 
ing rise to the spore nuclei. 

This order among the basidia fungi is analogous to the Exoas- 
cales among the ascus fungi. There are two genera and some 
twenty-five species. 

Key to Genera of Exobasidiales. 

Basidia 6-spored; not gall producers 1. Microstroma, p. 396. 

Basidia 4-spored ; producing galls 2. Exobasidium, p. 396. 

Microstroma Niessl. contains only three species of which 

M. album (Desm.) Sacc. is on oak; 

M. juglandis (Ber.) Sacc. on Juglans and Hicoria. 

Exobasidium Woronin 

Mycelium penetrating the host and causing distinct hyper- 
trophy, hymenium subcuticular, erumpent, basidia 4-spored, 
spores elongate. 

There are some twenty species, mostly on members of the 



THE FUNGI WHICH CAUSE PLANT DISEASE 



397 



Ericaceie. Cultural work and studies in infection are needed be- 
fore species can l)c properly delimited.^''' 

E. vaccinii (Fcl.) Wor. occurs on Vaccinium vitis idaia, forming 
large blisters on the leaves, 
rarely on petioles and stems, 
discoloration red or purple. 
The fungus appears as a 
white bloom on the under 
surface of the leaf; spores 
narrowly fusiform, 5-8 x 
1-2 M. 

Richards ^^ who studied 
E. vaccinii and E. an- 
dromedae from inoculations 
concludes : 

''Aside from the form of 
the distortion, E. vaccinii 
and E. andromedae cannot 
well be distinguished. The 
former can produce the same 
form of distortion on both 
Gaylussacia and Andromeda 
and the latter has been made 
to produce a similar growth 
on Andromeda. Micro- 
scopically these forms do 
not differ. The natural 
conclusion is that these two 
species of Exobasidium are 
one and the same and the form producing large bag-like dis- 
tortions on Andromeda should be considered a form of E. vac- 
cinii." 

E. oxycocci Rost causes greater hypertrophy than E. vac- 
cinii, distorting young twigs and leaves; spores 14-17 x 30 m; 
smaller conidia often present. The mycelium infests the leaves 
and stems of the cranberry. ''° Morphologically the species agrees 
closely with E. vaccinii. Infection experiments are needed. 

E. vexans Mas ^^ causes a serious disease on tea. E. andromedae 




Fig. 284. — Exobasidium andromedae on An- 
dromeda, showing host cells, mycelium, 
basidia and spores. After Richards. 



398 



THE FUNGI WHICH CAUSE PLANT DISEASE 



• --c 



'- ~i 



Pk., E. rhododendri Cram,, E. japonicum shirai and E. peckii 
Hal. are reported on Rhododendron and Andromeda; 

E. azaleae Pk. and several other species on various Rhododen- 
drons; E. vitis Prill, was noted in France on the grape; '^^ 

E. lauri (Borg) Geyl. is on Laurus. 

E. cinnamomi Petch on cinnamon in Ceylon. 

Agaricales (p. 395) '' ^' "• '*• "> "** 

This is a very large order of over eleven thousand species. 
The mycelium grows to long distances over or through the sup- 
porting nutrient me- 
dium, often forming 
conspicuous long-lived 
resistant rhizomorphic 
strands or sheets, some- 
times developing sclero- 
tia or again appearing 
as a mere floccose weft. 
The basidia bear four 
simple spores, in rare 
cases two, six or eight. 
Other forms of conidia 
are found in some spe- 
cies and chlamydospores 
may be borne either ex- 
ternally on the sporo- 
phore, in the hymenium, 
or inside of the sporo- 
phore tissue. In the 
lowest forms the basidia 
arise directly from the 
mycelium without the formation of any definite sporophore but 
in most species the sporophore is highly complex, consisting of 
large, stalked or sessile, pseudoparenchymatous structures (toad- 
stools, mushroom, etc.) on special surfaces of which, the hy- 
menium, Fig. 286, lies; covering gills or spines or Uning pits or 
pores. 

The general relation of the basidia to the hymenium and the 




- rac 



Fig. 285. — An agaric (Amanita) sporophore show- 
ing parts; c, pileus; m, c, striated margin; g, gills; 
a, annulus; s, stem; v, volva; mc, mycelium. 
After Peck. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



399 








sporophore is shown in Figs. 285, 286. Families are delimited 
by the character of the sporophore, distribution of the hymenial 
surfaces, presence of cystidia, size q^ ^rt) rrn ■; 
and color of spores, and other more IT^Jl-^-Jl-- 
minor points. \(j )i! f if 

In germination the spore pro- "^'^'"'j ;:-f-^:yr 
duces a germ tube which develops vV^"^^'^ ^- 
directly into a mycelium. In many ?-— ^- 
species the young mycelium is 
conidia-bearing. 

Cytologically the group conforms 
to the general description given on 
pages 393, 394. 

The Agaricales are chiefly of in- 
terest to pathologists as wood fungi 
though in a comparatively few in- 
stances they are found on herbs. 
Upon wood they may do harm. 
First, as root parasites, in which 
case death may follow through in- 
terference with absorption or an- 
chorage. Second, as causes of 
heart rots leading to weakness and 
eventual overthrow of the tree. 
Third, as parasites of sap wood, 
cambium or bark leading to death 
of a part of the host and often its 
complete loss. 

In many instances the fungus 
draws its subsistence from host 
cells not actually alive and hence strictly speaking they are 
saprophytes. Nevertheless, since their ultimate effect upon the 
tree is to cause disease or death, from the practical viewpoint 
these fungi are pathogenic. Many species, moreover, can start 
their career on a host plant as saprophytes and after attaining a 
stage of vigorous vegetative growth become truly parasitic. In 
most instances they are wound parasites, which cannot gain ac- 
cess to the inner portions of the host through uninjured tissue 




Fig. 286. — Cross section of the gill 
showing basidia, sterigmata and 
spores, also a cystidium stretch- 
ing from one gill to the next. 
After Buller. 



400 



THE FUNGI WHICH CAUSE PLANT DISEASE 








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w;a cS.M>>^ >^ "^ a. g- 

B'S " E"(D « P a o 03 

S =S . S I '^-^ o =-' c 

S^ a:n ^o 3^ S^-^ o 
•2« §-53^ =« 2"^ ^ § " ^, 

TpS £ MO) oj^ &S'> S "h 



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CQ 






a . -M OS o G " o 
§ o ^.S ^^ ^< 



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0) £. H b 



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f^ : ; : : 



THE FUNGI WHICH CAUSE PLANT DISEASE 



401 




but must make entrance through some wound, as those due to 
hail, wind, snow, insects, men and other animals, 
etc., which exposes the inner bark, cambium, sap 
wood or heart wood without its natural outer 
protecting tissues. 

Within the tissues the mycelium may cause the 
disappearance of substances, e. g., Fomes ig- 
niarius consumes the tannin, or the mycelium 
may secrete enzymes which penetrate the host to fig. 288. — Tra- 
long distances. These may dissolve first one com- 
ponent of the cell, e. g., the lignin, next the 
most lignified residue, the middle lamella, re- 
sulting in dissolution of the tissue. In other cases 
the parts of the cell walls other than the middle 
lamella are first affected and soon shrink resulting 
in cracks. Fig. 289. Some fungi cause character- 
istic color changes particularly in those cell walls 
which are rich in carbon. Parasitism in this 
group is old since good examples of agarics 
growing on wood are found as early as in 
period. ^^ 

These fungi spread to new hosts by spores borne in various 
ways; by insects (Trametes radiciperda) animals, 
wind (Polyporus pinicola) etc., or in a purely 
vegetative manner by the mycelium which in the 
form of rhizomorphs (Armillaria mellea) travels 
through the ground to considerable distances. 
An excellent summary of the early history of our 
knowledge of wood destroying fungi is given by 



cheid of pine 
decomposed by 
Trametes pini. 
The primary 
wall dissolved 
as far as aa; 
in the lower 
part the sec- 
ondary and ter- 
tiary layers are 
only of cellu- 
lose; c, myce- 
lium making 
holes at d and 
e. After Har- 
tig. 

the Tertiary 



Fig. 289. — Pine 



1, 338 



traciieid acted Buller, 

porus^schw^- The number of species of Agaricales which af- 
nitzii. The fgg^, five plants in the waj^s mentioned above is 

cellulose has ^. . ,.,. 

been extracted very great but m many mstances research m this 
w^aUs^chiefly field has not yet revealed the true relation existing 
hgnm. Drymg bg^ween the fungi and the woody plants upon 
cracks. After which they are found growing; whether they 
occur as parasites or as saprophytes; whether 
actually injurious or not. The species given below are mainly 



402 THE FUNGI WHICH CAUSE PLANT DISEASE 

regarded as actually injurious. If more questionable cases were 
to be included the number would be increased several fold. 



Key to Families of Agaricales 

Basidia loosely aggregated on a mold-like 
or arachnoid base, formed from loose 

floccose hyphae 1. Hypochnaceae, p. 402. 

Basidia closely aggregated, forming a com- 
pact layer 
Hymenium smooth 

Sporocarp effused, resupinate or rarely 

pileate, usually not fleshy 2. Thelephoraceae, p. 405. 

Sporocarp clavate, the upper portion 

only sporogenous, usually fleshy. . 3. Clavariaceae, p. 412. 
Hymenium variously folded or pitted 
Hymenium with teeth, tubercles or 
tooth-like plates which are sporo- 
genous 4. Hydnaceae, p. 413. 

Hymenium lining pores 
Pores not easily separating from the 
pileus, which is commonly 

leathery, corky or punky 5. Polyporaceae, p. 416. 

Pores readily separating from the 

pileus which is fleshy 6. Boletaceae, p. 440. 

Hymenium covering the surface of 

radiating plates 7. Agaricaceae, p. 442. 



Hypochnaceae 

Sporophore poorly developed and often indefinite, of loosely 
woven floccose hyphae; the basidia clavate, loosely aggregated 
into an ill-defined hymenium. 

In the simplicity of the sporogenous structures the members 
of the group approach the Hyphomycetes from which they are 
separated only by their sporophores which are of the nature of 
basidia rather than of ordinary conidiophores. 

A small family of some half dozen genera and sixty species. 



THE FUNGI WHICH CAUSE PLANT DISEASE 403 



Key to Genera of Hypochnaceae 

Spores colorless, smooth, rarely granular 
Basidia with two sterigmata 

Basidia circulate 1- Helicobasidium. 

Basidia not circinate 

Basidia pyriform, beaked 2. Urobasidium. 

Basidia clavate, not beaked 3. Matruchotia. 

Basidia with 2-4 rarely 6 sterigmata 4. Hypochnus, p. 403. 

Basidia with numerous sterigmata 

Sterigmata small 5. Aureobasidium, p. 405. 

Sterigmata large 6. Pachysterigma. 

Spores colored, mostly spiny 7. Tomentella. 

Hypochnus Ehrenberg. 

Floccose or fungoid, rarely thinly fleshy, spreading over the 
substratum; basidia clavate; spores colorless, smooth or minutely 
granular. 

This genus which contains half the species of the family, is 




Fig 290. — H. ochroleucus sporogenous reticulum prior to spore formation. 
8 basidia, sterigmata, and spores. After Stevens and Hall. 

with difficulty distinguished from Corticium from which it differs 
in the character of its hymenium. 

H. ochroleucus N. ^''"''^ Sporogenous reticulum of a very close, 
irregular net work of hyphae variable in thickness; basidia scattered, 



404 



THE FUNGI WHICH CAUSE PLANT DISEASE 



clavate, swollen; sterigmata 4; spores oblong, slightly flattened on 
the side adjacent to the companion spores, tapering slightly at 
each end, 4.7-5.8 x 10.5-11.6 /x. A migratory mycelium is 
present, covering twigs and leaves with a brown felty growth; 
rhizomorphs white, later buff, about 5.8 /x, septate. Sclerotia 
are also found. 

The long cottony rhizomorphic strands extend along the twigs, 
up the petioles and in places aggregate to form brown sclerotia, 




Fig. 291. — H y p o c h ii u s, 
semi-diagrammatic sec- 
tion showing develop- 
ment of hymenium and 
basidia, with nuclear 
conditions. After Har- 
per. 





Fig. 292. — Mycelium 
of Hypochnus show- 
ing clamp connec- 
tions. After Har- 
per. 



which are especially abundant near the terminal buds. On the 
leaves Stevens and Hall ^^' '*^ describe a loose network from which 
the basidia arise. Fig. 295. The species is found on apple, pear, 
lilac, quince, Vibernum and probably other hosts, and is widely 
distributed. 

H. cucumeris Frank. 

Fungus gray or brown; basidia elongate, bearing 4 sterigmata; 
spores ovoid hyaline. Reported on cucumbers ^''' ^^ in 1883. 

H. solani P. & D. is said to be a parasite of potatoes. ^^ It is 
probably identical with Corticium vagum solani. See p. 407. 



/ 



THE FUNGI WHICH CAUSE PLANT DISEASE 405 

H. theae Bern, occurs on tea; ^^ H. filamentosus Pat. on live 
leaves of Caryophyllacese and Amaryllidacese in Quito; H. fu- 
ciformis (Berk.) McAlp on grasses in Australia. 

An undetermined species of Hypochnus was studied by Eustace^ ^ 
as the cause of rot of stored apples. Artificial inoculations proved 
its parasitism, though it was unable to make entrance through 
sound surfaces. 

The spores are hyaline, smooth, usually obovate, 4-5.5 x 2.5-3.5 n. 

Aureobasidium Viala & Boyer ^^ (p. 403) 

The fungus body consists of delicate, floccose, more or less 
webby masses of much-branched, septate, golden hyphse; basidia 
with numerous sterigmata; spores cylindric. 

A single species, A. vitis, V. & B., occurs on grape roots in 
France and Italy^'' ^" 

Thelephoraceae (p. 402) 

Sporocarp leathery or membranous, (rarely fleshy, corky or 
punky) resupinate or pileate, simple or compound; hymenophore 
smooth, warty or wrinkled; basidia numerous, interspersed with 
spine-like cystidia. 

This is a very large family, but of its eleven hundred species 
only a few are parasites. 

Key to Genera of Thelephoraceae 

Hymenophore without cj^stidia 
Hymenophore entirely resupinate 
Spore membrane colorless 
Contents colorless 
Spores sessile 
Basidia with 2 sterigmata. . . 1. Cerocorticium. 
Basidia with 4 sterigmata. ... 2. Corticium, p. 406. 
Basidia without sterigmata. . 3. Protocoronospora,p.409. 

Spores stalked 4. Michenera. 

Contents colored 5. Aleurodiscus. 

Spore membrane colored 

Hymenophore soon gelatinous .... 6. Aldridgea. 
Hymenophore fleshy-leathery. ... 7. Coniophora. 
Hymenophore partially free, shelving 

Context of several layers .8. Stereum, p. 409. 



406 THE FUNGI WHICH CAUSE PLANT DISEASE 

Context of only one layer 
Hymenophore leathery 
Hymenium not ribbed 

Hymenium almost smooth or 
with warts 

Basidia continuous 9. Thelephora, p. 410. 

Basidia septate 10. Septobasidium, p. 411. 

Hymenophore smooth 11. Hypoly ssus. 

Hymenium with ribs 

Ribs becoming warty 12. Cladoderris. 

Ribs with warty spines 13. Beccariella. 

Hymenophore not leathery 

Hymenophore gelatinous-fleshy 14. Phlebophora. 
Hymenophore membranous, rare- 
ly fleshy or fleshy-leathery 
Hymenium exterior to the 

hymenophore 15. Craterellus. 

Hymenium inside the hy- 
menophore 
Hymenophores mostly soli- 
tary 
Hymenophore sessile or 

laterally stipitate 16. Cyphella. 

Hymenophore centrally 

attached - 17. Discocyphella. 

Hymenophores closely 

grouped 18. Solenia. 

Hymenophore with cystidia 
Cystidia of a single cell 
Cystidia unbranched 
Hymenophore of a single layer 

Hymenophore resupinate 19. Peniophora. 

Hymenophore laterally short- 
stalked 20. Skepperia. 

Hymenophore of several layers. . . 21. Hymenochaete, p. 411. 

Cystidia stellate-branched . 22. Asterostroma. 

Cystidia of several cells 23. Bonia. 

Corticium Persoon (p. 405) 

Hymenophore homogeneous in structure, membranous, leathery 
or fleshy, almost waxy, rarely approaching gelatinous; hymenium 



THE FUxNGI WHICH CAUSE PLANT DISEASE 



407 



arising immediately from the mycelium, smooth or minutely 
warty; basidia clavate, with four sterigmata; spores small, globose 
or ellipsoid, with a smooth colorless membrane. 

A genus of some two hundred fifty species, mostly wood inhab- 
iting. 

One species possesses a mycelium which has long been known 
in its sterile form as a Rhizoctonia. 

Corticium vagum solani Burt. ''^■^*'' ^^'* 

Hymenophore, white when sporing, poorly developed, of loosely 
interwoven hyphse; basidia short, cylindric or oblong; spores some- 





FiG. 293. — C. vagum solani Rhizoc- 
tonia stage. After Duggar. 



Fig. 294. — C. vagum-solani, 
basidia, sterigmata and 
spores. After Rolfs. 



what elliptic, often irregular in outline, 9-15 x 6-13 ix. 

Sterile mycelium ( = Rhizoctonia solani = Rhizoctonia violacea)^^ 
turning yellowish with age, and branching approximately at 
right angles; often forming sclerotia-like tufts wdth short, broad 
cells more or less triangular which function as chlamydospores. 

Brown to black sclerotial structures, a few millimeters in diam- 
eter, consisting of coarse, broad, short-celled hyphae of peculiar 
and characteristic branching also occur freely, both in nature and 
in culture, Fig. 293. These cells seem capable of functioning as 
chlamydospores. 

The hymenophore consists of a dark network of hyphae which 
changes to grayish-white when sporing. It frequently entirely 
surrounds the green stems of the host near the ground. The tips of 
the outermost hyphse are sterigmatate. The spores germinate 
readily, developing into typical Rhizoctonia mycelium. 

The relation which the various Rhizoctonias which have been 
described on numerous hosts may bear to the one species under 



408 THE FUNGI WHICH CAUSE PLANT DISEASE 

discussion is problematic. Much culture and inoculation work is 
needed. Some of the various hosts upon which a Rhizoctonia 
apparently closely allied to that of Corticium vagum solani have 
thus far been found in America are : 

Sugar-beet, bean, carrot, cabbage, cotton, lettuce, potato, 
radish, sweet potato, pumpkin, watermelon, garden pea, corn, 
purslane, Solanum verbascifolium, egg plant, pig-weed, spiny 
pig-weed, Heterotheca subaxillaris, Richardia, Crotalaria, Cy- 
perus rotundus, Heterotheca lamarckii and Phytolacca decandra, 
Pinus sps., • Picea. Pseudotsuga, carnation and alfalfa. 

The sterile mycelium was noted in Europe on potato many years 
ago ; its existence in America has been known since 1890 (Duggar ^^) . 
Its identity with the genus Corticium was demonstrated in 1904 
by Rolfs ''^ both by observing the connection between the myce- 
lium and the basidia on young potato plants and by culture of 
the typical Rhizoctonia stage from the basidiospores. The parasi- 
tism of the organism was proved by inoculations made with pure 
culture by Rolfs.'^^ 

The sterile mycelium (Rhizoctonia) occurs in two forms on 
the potato, a light-colored actively parasitic form usually some- 
what deep in the affected tubers and a darker mycelium growing 
superficially on the host or over the soil. In artificial culture the 
manner of branching is typical, the young branches running 
nearly parallel to the main thread and bearing slight constrictions 
at their bases. 

A key to the species in France is given by Bourdot and Gol- 
zin.164 

C. laetum (Karst.) Bres. 

Plant body at first salmon-colored, soon fading to a dirty-white; 
context, of hyphse which are nodose, septate, irregular, 4-10 /x, 
basidia clavate, 35-50 x 7-12 n; spores oblong ovate, subde- 
pressed on one side, hyaline, 10-14 x 6-8 fi. 

On fig and apple in Louisiana, and in Europe and in the Northern 
United States on Alnus, and Corylus. It causes the limb blight 
of the fig, ^^' ^^^ gaining entrance through dead twigs. While the 
fungus is usually a saprophyte, once it gains entrance to the host 
it follows down the branch, covering it with its bright salmon- 
colored fructification and causing sudden wilting and dying of the 



J" 



THE FUNGI WHICH CAUSE PLANT DISEASE 409 

leaves. The cambium layer is the seat of the disease. The fungus 
spreads rapidly but is not a serious pathogen except in rainy periods 
in midsummer. 

C. javanicum (Hen.) S. & S. causes disease of coffee and tea; ^^ 
C. dendriticum Hen. parasitizes orange stems; ''^ C. comedens 
(Nees) Fr. occurs on oak as a wound parasite; C. zimmermannii 
S. & Syd. injures many tropical trees; ^° C. lilacino-fuscum Berk. 
& Curt, occurs on cacao. 

C. chrysanthemi Plow, is reported as the cause of death of 
cultivated chrysanthemum in England. 

Protocoronospora Atkinson & Edgerton (p. 405) 

Genus as in Corticium, except for the basidia which bear 4-8 
sessile, oblong or elliptic spores. 

P. nigricans Atk. & Edg.^^ forms narrow elongate spots on vetch 
pods, stems and leaves. Spot, ol^lique on the pods, 2-5 x 1-2 mm., 
at first white or with a purple border, later black; subhymenial 
layer subepidermal two or three cell layers thick; basidia clavate, 
to subcylindric, 20-30 x 6-8 /x; spores sessile, pale-pink in mass, 
oblong to subelliptic, hyaline, smooth, granular, continuous, or 
1-septate in germination, straight or curved. Found on vetch at 
Ithaca, N. Y., associated with Ascochyta. 

Stereum Persoon (p. 405) 

Hymenophore leathery or woody, persistent, of several layers, 
sometimes perennial, laterally or centrally attached; hymenium 
smooth. 

A genus of about two hundred fifty species chiefly wood in- 
habiting, but a few grow in humus. 

S. hirsutum (Willd.) Pers. 

Hymenophore leathery, firm, expanded, wrinkled, hairy, yellow- 
ish; the hymenium yellowish, smooth. 

It causes a rot of oak in which the wood appears white-spotted 
in cross section. 

S. quercinum Potter,^- is found on oak in Europe. 

S. frustulosum (Pers.) Fries, though sometimes found on living 
trees, is confined to dead wood. It causes a speckled rot of oak 
wood.^^ Fig. 295. 



410 



THE FUNGI WHICH CAUSE PLANT DISEASE 



S. purpureum Pers. 

Hymenophore expanded, leathery, arched, grayish -white; hy- 
menium smooth, purple. 

This species is constantly associated with an English and Cana- 
dian disease of drupaceous and pomaceous trees, manifest by a 




Fig. 295. — Oak timber rotted by Stereum frustulosum. The 
lighter colored, irregular, small bodies are sporophores. After 
von Schrenk and Spaulding. 

silvering of the leaves, death of branches and finally of the tree. 
The causal agency of the fungus has not been fully established.^^ 

Cosmopolitan in distribution. 

S. rugosum Fr. parasitizes the cherry laurel. 

Thelephora Ehrenberg (p. 406) 

Hymenophore leathery, context similar, variable in form, 
sessile or pileate, even or more commonly plicate; hymenium con- 
fined to the lower surface or extending all over the hj^meno- 
phore, smooth or uneven, sometimes warty; basidia numerous, 
clavate; spores elongate, membrane often dull broAvn, and granular. 



N 



THE FUNGI WHICH CAUSE PLANT DISEASE 



411 



T. laciniata Pers. injures various trees by its leathery incrustations. 

T. galactina Fr. , .,1 • i 

Resupinate, broadly effused, encrusted, smooth, milky m color. 
The root rot on oak is in type much like that caused by Armillana 




Fig. 296.— Telephora laciniata. After Clemeuts. 

mellea. It also causes a root rot of apple trees throughout the 

Central States.^^ . , 

Hymenochaetse noxia Berk, is a practically omnivorous fungus 
attacking hevea, cacao, tea, dadap, castilloa, Caravomca cotton, 
bread fruit, camphor, throughout the eastern tropics. 

Septobasidium Pat. (p. 406) 
As Thelephora but with septate basidia. 



412 THE FUNGI WHICH CAUSE PLANT DISEASE 

S. pedicillata (Schw.) Pat.*'^ 

Resupinate, effused, byssoid, subcompact, light cinnamon- 
yellow to white, hymenium smooth. 

On oak, palmetto, tupelo, apple, etc. Cosmopolitan. 

Clavariaceae (p. 402) 

Hymenophore fleshy, leathery, cartilaginous or waxy, cylin- 
dric-clavate, simple or branched often quite large and conspicuous 
hymenium with cystidia; basidia clavate, with 1 to 4 sterigmata; 
spores elliptic or fusiform, hyaline. 

There are about five hundred species. One genus only is para- 
sitic. 

Key to Genera of Clavariaceae 

Hymenophore small, simple 
Basidia with 1 or 2 sterigmata 

Spores colored 1. Baumanniella. 

Spores hyaline 

Hymenophore expanded above into a 

cap, basidia with 1 sterigma. ... 2. Gloeocephala. 
Hymenophore clavate, basidia with 

2 sterigmata 3. Pistillaria. 

Basidia with 4 sterigmata 

Hymenophore clavate or filiform. ... 4. Typhula, p. 412. 

Hymenophore capitate, hollow 5. Physalacria. 

Hymenophore usually large, branched, 
rarely simple 
Hymenophore mostly round, branches 
never leaf -like 

Hymenophore fieshy 6. Clavaria. 

Hymenophore not fleshy 

Hymenophore cartilaginous or horny. 7. Pterula. 
Hymenophore leathery and hairy .. . 8. Lachnocladium. 
Hymenophore leaf-like 9. Sparassis. 

Typhula graminum Karst. has been reported as injuring wheat. 

Hymenophore fleshy or waxy, delicate, simple or rarely branched, 
filiform or cylindric, clavate; spores colorless. Sometimes forming 
sclerotia. Fig. 297. 

T. variabilis Riess. is regarded as a parasite of beets. 



r 



THE FUNGI WHICH CAUSE PLANT DISEASE 



413 



Hydnaceae (p. 402) 

Sporophore variable in texture, cu- 
ticular, leathery, corky, felty, fleshy or 
woody; free and stipitate, shelving 
or resupinate; the hymenium warty, 
thorny, spiny or with tooth-like 
plates; basidia usually 4-spored, rarely 
1-spored. 

Over five hundred species, mostly 
very limited in tlieir geographical 
distribution, and chiefly epixylous, 
although some are humus-loving. 




297.— Typhula 
habit sketch; n, 



variabilis, 
basidium 



and spores. After Winter. 



Key to Gener.\ of Hydnaceae 

Sporophore annual 

Hymenium without a subiculum 1. Mucronella. 

Hymenium with a subiculum. 
Hymenium with folds or wrinkles 

Crest of the folds entire 2. Phlebia. 

Crest of the folds incised 3. Lopharia. 

Hymenium with granules or warts 
Granules penicillate, multifid 

Hymenophore fleshy , 4. Kneiffiella. 

Hymenophore firm, not fleshy. ... 5. Odontia. 
Granules simple 

Hymenium porose, reticulate, 

granular 6. Asterodon. 

Hymenium with obtuse cylindric 

warts 7. Radulum. 

Hymenium with globose hollowed 

warts 8. Grandinia. 

Hymenium with more or less subulate 
teeth or spines 

Pileus clavaria-like 9. Hericium. 

Pileus not clavaria-like 
Teeth free, mostly fleshy 
Teeth rounded. 



414 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Spores hyaline 10. Hydnum, p. 414. 

Spores colored 11. Phaeodon. 

Teeth lammeliform 12. Sistotrema. 

Teeth connected at base, coriaceous 

Cystidia none 13. Irpex, p. 415. 

Cystidia present 14. Hydnochaete. 

Sporophore perennial, punky or woody 

Upper surface smooth, or sulcatc 15. Echinodontium, p.415. 

Upper surface zonate 16. Steccherinum, p. 416. 

Hydnum Linnaeus 

Sporophore cuticular, leathery, corky, woody or fleshy, variable 
in form, resupinate; pileus, shelving, or bushy branched; hymenium 
beset with pointed spines; basidia with 4 sterigmata; spores hya- 
line. 

The species of this genus, between two hundred fifty and three 

hundred, are mostly sapro- 
phytes but a few are true 
parasites on woody plants. 
H. erinaceus Bul.^^ 
Cap 5-30 cm. wide, white, 
then yellowish or somewhat 
brownish, the branches form- 
ing a dense head covered 
with teeth, fleshy; stem 
short and stout, 2-8 cm. long 
and thick, or entirely lack- 
ing; teeth 3-10 cm, long, 
slender, densely crowded ; 
spores globose, clear, 5-6 fi. 
The name refers to the ap- 
pearance of the head. 
It is the cause of a white rot on many deciduous trees, chiefly 
oaks. The rotted wood is soft and mushy. Numerous large holes 
filled with masses of light yellowish fluffy mycelium occur in the 
heart-wood. Sporophores are often absent on the rotted tree. 
H. septentrionale Fr.^^ 
Sporophores in bracket-like clusters, up to 20-30 cm. wide by 




Fiu. 298. — Fruiting body of Hydnum erina- 
ceus in a hollow log. After von Schrenk 
and Spaulding. 



^ 



THE FUNGI WHICH CAUSE PLANT DISEASE 



415 



50-80 cm. long, creamy white in color, texture at first fleshy, be- 
coming more fibrous; pileus often 3 cm. thick, upper surface al- 
most plain, slightly scaly, all pilei united behind, teeth slender, 
often 12 mm. long. 

On sugar maple, })eech, etc., causing rot of the heart-wood. 

H. diversidens Fr. causes white rot of oak and beech in Europe. 

H. schiedermayeri Heuff,®^ injures apple trees in Europe. 



Irpex Fries (p, 414) 

Sporophore shelving or resupinate, hymenium on the lower side, 
from the first toothed; teeth firm, subcoriaceous, acute, continuous 




Fig. 2'J'J. — 1. flavus. H, habit sketch. After Hennings. 



with the pileus, arranged in rows or reticulately, basally widened 
and lamellate or even fa void; basidia 4-spored. 

I. fusco-violaceus (Schrad) Fr.^^ is a wound parasite on pine in 
Europe. 

I. flavus Klotsch is injurious to the Para rubl^er, cloves and 
coffee; I. destruens to tea. 

I. paradoxus (Schrad) Fr., according to Glazan,^" causes timber 
rot. 

Echinodontium EUis & Everhart (p. 414) 

Similar to Hydnum but differing in perennial habit; pileus, 
smooth, woody; cystidia bearing spines. 

E. tinctorium E. & E.^^' ^'^ is the only species. 

Spines brown, 1 cm. long, 134"~2 mm. broad; cystidia subconic, 
reddish-brown, 20-30 x 6-7 ju- 



416 THE FUNGI WHICH CAUSE PLANT DISEASE 

On living trunks of Tsuga, Pseudotsuga °°° and Abies in north- 
western North America. 

Steccherinum S. F. Gray (p. 414) 

Perennial, pileate, sulcate, zonate, radiately subrugose; teeth 
wide, irregular. 

S. ballouii Banker is the single economic species. 

Campanulate to subdimidiate, more or less intricate, sessile, 
decurrent to pendent, 1-4 x 1-5 cm. laterally connate up to 10 cm. ; 
surface velutinous when young, often licheniferous at base, dark 
olive-brown, drying gray-brown in older parts and seal-brown 
in younger; margin obtuse, seal brown; substance thin, 1-2 mm., 
of two layers, the upper harder, somewhat brittle, dark brown, 
lower softer and lighter colored; hymenium colliculose, golden- 
yellow, fading to buff or cream; teeth variable, subterete to diform, 
confluent, papalloid to elongate, usually obtuse, tips brownish, 
1-5 X 0.5-1 mm. irregularly distributed; spores hyaline broadly 
elliptic to subglobose, 7-7.2 x 5.5-6.5 /x. 

On Chamaecyparis in New Jersey .^^ According to Ballou ^^ 
this fungus is devastating the forests of swamp cedar in New Jersey. 
As it grows only in the tops of the tree and dies with the host, the 
dead sporophores soon disappearing, it is a species not easily 
observed. 

Polyporaceae (402) 

Sporophore annual or perennial; context fleshy, tough, corky 
or woody; hyn^enium poroid or lamelloid, fleshy to woody, rarely 
gelatinous. 

The sporophores are sometimes fleshy, even edible liut they are 
more commonly hard and woody, occurring as bracket forms, 
Fig. 310, on tree trunks. 

Key to Genera of Polyporaceae 

Pores reduced to shallow pits separated by : '^ * ; ; 

narrow ridges, folds or reticulations. . ." I. Merulieae, p. 418Li ; .; . , 
Pores well developed, variable in size and :^i M 

form II. Polyporeae. 

Sporophore, at least in part gelatinous 



THE FUNGI WHICH CAUSE PLANT DISEASE 



417 



Sporophore more or less gelatinous 

throughout 1. Laschia. 

Sporophore leathery above, the pores 

gelatuious 2. Glceoporus. 

Sporophore leathery, corky or punky, 
never gelatinous. Pores minute and 
rounded or large and angular 
Sporophore rcsupinate, never shelv- 
ing 3. Poria, p. 418. 

Sporoi)hore normally pileate, only ac- 
cidently resupinate 
Pores usuall}^ small or medium sized, 
and round 
Substance of the pileus not con- 
tinuing between the pores 
Sporophore at first fleshy, then 

hardening 4. Polyporus, p. 418. 

Sporophore from the first 
leathery or spongy usually 

annual. 5. Polystictus, p. 426. 

Sporophore from the first more 
or less corky or punky, 

usually perennial 6. Femes, p. 428. 

Substance of the pileus continued 

between the pores 7. Trametes, p. 437. 

Pores usually large, hexagonal or 
labyrinthiform rarely bounded 
by large plates 
Pores hexagonal 
Stipe lateral; pores elongate. ... S. Favolus, p. 439. 

Sessile; pores regular 9. Hexagonia. 

Pores labyrinthine, or replaced by 
plates 
Sporophore sessile 

Hymenium labyrinthine, be- 
coming irpiciform 10. Daedalea, p. 439. 

Hjrmenium lamellate, not be- 
coming irpiciform 11. Lenzites, p. 439. 

Sporophore stipitate, concentri- 
cally furrowed 12. Cyclomyces. 



418 THE FUNGI WHICH CAUSE PLANT DISEASE 

Merulius lachrymans of the tribe Merulieae is said to parasitize 
violets. 

Poria Persoon (p. 417) 

Sporophore entirely resupinate, often widely extended, the 
base leathery to punky, pores small, rounded, covering almost the 
entire surface. 

A genus of almost three hundred species. 

P. laevigata Fr. causes a white rot of the birch. 

P. vaporaria (Pers.) Fr. is a wound parasite on coniferous trees ^^ 
especially common on spruce and fir causing a brown rot of the sap 
wood. 

P. subacida Pers.^* Sporophore effused, determinate; margin 
pubescent, white; pores minute, subrotund, 2-6 mm. oblique, 
odor subacrid. A common saprophyte on deciduous and conif- 
erous trees especially, pine, hemlock, and spruce. Irregular 
cavities form within the diseased wood and become lined with a 
tough felt of hyphse, yellow on the inner side. 

P. hypolaterita Berk, causes a tea disease in Ceylon.^^ 

P. vineta Berk, is reported as causing a rot of Hevea in Ceylon.''^ 

Polyporus (Micheli) Paulet (p. 417) 

Sporophore usually annual; simple or compound, rather thick, 
fleshy, leathery or corky, stipitate or shelving, pores developing 
from the base toward the margin. Grading into Polystictus on 
the one hand and approaching Fomes on the other. 

There are about five hundred species. 

P. obtusus Berk.*'^' ^^ 

Pileus somewhat imbricate, large and spongy, at length indurate, 
dimidiate, sessile, often ungulate, 5-7 x 10-15 x 3-5 cm.; surface 
spongy-tomentose, hirtose, azonate, smooth, sordid-white to 
isabelline or fulvous; margin very thick and rounded, sterile, 
entire, concolorous; context spongy-fibrous, white, indurate with 
age especially below, 1-2 cm. thick; tubes very long, 2-3 cm., 
white to isabelline within, mouths large, irregular, often sinuous, 
1-2 mm. broad, edges thin, "fimbriate-dentate to slightly lacerate, 
white to isabelline, at length bay and resinous in appearance; spores 
globose, smooth, hyaline, 6-8 /x; hyphai hyaline, 6 ix; cystidia none. 



s 



THE FUNGI WHICH CAl'SE PLANT DISEASE 



419 



It causes a heart-rot of living oaks, occurring as a wound parasite 
and invading the sap wood when decay is well advanced. It is 
also found on black locust 



332 
66, 67, 78, 74. 79, 80 




P. sulphureus (Bui.) Fr. 

Hymenophore cespitose-multiplex, 30-60 cm. broad; pileus 
cheesy, not becoming rigid, reniform, very broad, more or less 
stipitate, 5-15 x 7-20 x 
0.5-1 cm. ; surface finel} 
tomentose to glabrous, 
rugose, anoderm, sub- 
zonate at times, vary- 
ing from lemon-yellow 
to orange, fading out 
with age; margin thin, 
fertile, concolorous, 
subzonate, finely to- 
m e n to s e, undulate, 
rarely lobed; context 
cheesy, very fragile 
when dry, yellow when 
fresh, usually white in 
dried specimens, homogenous, 3-7 mm. thick; tubes annual, 
2-3 mm. long, sulphur-yellow within; mouths minute, angular, 
somewhat irregular, 3-4 to a mm., edges very thin, lacerate, 
sulphur-yellow, with color fairly permanent in dried specimens; 
spores ovoid, smooth or finely papillate, hyaline, 6-8 x 3-5 fx. 

It is common as a cause of red heart-rot of forest and shade 
trees, conifers and deciduous, and also does damage in the orchard, 
especially on cherry, apple and pear, and in the forest to oak, chest- 
nut, poplar, maple, walnut, butternut, alder, locust, ash, pine, 
hemlock, larch. 

The decayed wood resembles a mass of red-l)rown charcoal and 
is characterized by radial or concentric cracks in which the fungus 
forms thin leathery sheets. In dicotyledons the vessels become 
filled with the fungus. Round gonidia are often formed within 
the wood. 

P. squamosus (Huds.) Fr. ' ' 

Sporophore of immense size, reaching 50 cm. in breadth and 3 cm. 



Fig. 300. — Polyporus sulphureus. Scattered fruit 
bodies on living oak. After Atkinson. 



420 



THE FUNGI WHICH CAUSE PLANT DISEASE 



in thickness, usually found in imbricated masses projecting from 
the trunks of living trees. Pileus subcircular and umbilicate when 
young, soon becoming flabelliform and explanate; surface ochra- 
ceous to fulvous, covered with broad, appressed, darker scales 




Fig. 301. — Polyporus squamosus. After Clements. 

which are very close together in young specimens; margin in- 
volute, thin, entire; context fleshy-tough, juicy, milk-white; very 
thick, odor strong; tubes decurrent, white or pale yellowish, very 
short, mouths large, alveolar, 1 mm. or more in diameter, edges 
thin at maturity, toothed at an early age, becoming lacerate: 
spores broadly ovoid, smooth, hyaline, 5 x 12 /x; stipe excentric 
to lateral, obese, reticulate above, clothed at the base with short, 



J' 



THE FUNGI WHICH CAUSE PLANT DISEASE 421 

dark brown or black, velvety tomentum, often reduced, variable 
in length. 

The mycelium causes white rot of nut, ornamental and fruit 
trees, particularly maple, pear, oak, elm, walnut, linden, willow, 
ash, birch, chestnut, beech, growing on dead parts of living trees. 
The hyphse advance most rapidly along the wood vessels and 
often bear clamp connections. 

181 

A beautiful biological study has been published by Buller ' 
who states that a single sporophore may produce 11,112,500,000 
spores and that "the number produced by a single fungus from a 
single tree in the course of a year may, therefore, be some fifty 
times the population of the globe." 

He showed the following enzymes to be present in the sporo- 
phore: laccase, tyrosinase, amylase, emulsin, protease, lipase, 
rennetase, and coagulase. Pectase, maltase, invertase, trehalase 
and cytase were not found; It is evident, however, that the my- 
celium in wood produces cytase and possibly hadromase. 

P. hispidus Bui. 

Pileus thick, compact, fleshy to spongy, dimidiate, sometimes 
imbricate, compressed-ungulate, 7-10 x 10-15 x 3-5 cm.; surface 
hirsute, ferruginous to fulvous, azonate, smooth; margin obtuse, 
velvety; context spongy-corky, somewhat fragile when dry, fer- 
ruginous to fulvous, blackening with age, 1-1.5 cm. thick; tubes 
slender, about 1 cm. long, ferruginous within, mouths angular, 
2-3 to a mm. ferruginous to bay, blackening with age, edges thin, 
very fragile, lacerate; spores broadly ovoid, smooth, thick-walled, 
deep-ferruginous, 2-guttulate, 5-6 x 7-8 /x. 

It is common on all kinds of deciduous trees, often injuring fruit 
trees, especially the apple. 

P. giganteus (Pers.) Fr. has been reported as injurious to the 
oak. 

P. glivus Fr. is a common saprophyte on deciduous trees and in 
some cases may be parasitic. 

P. dryophilus Berk. 

Pileus thick, unequal, unguliform, subimbricate, rigid, 7-8 x 10- 
14 X 2-3 cm. ; surface hoary-flavous to ferruginous-fulvous, becom- 
ing scabrous and bay with age; margin thick, usually obtuse, 
sterile, pallid, entire or undulate: context ferruginous to fulvous, 



422 



THE FUNGI WHICH CAUSE PLANT DISEASE 



zonate, shining, 3-10 mm. thick; tubes slender, concolorous with 
the context, about 1 cm. long, mouths regular, angular, 2-3 to a 
mm., glistening, whitish-isabelline to dark-fulvous, edges thin, 




Fig. 302. — Decomposition of spruce-timber by Polyporus boiealis. a, a 
tracheid containing a strong mycelial growth and a brownish yellow fluid 
which has originated in a medullary ray; at h and c the mycelium is still 
brownish. At d and e the walls have become attenuated and perforated, 
the filaments delicate; at / the pits are almost destroyed; at g and h only 
fragments of the walls remain." The various stages in the destruction 
of the bordered pits are to be followed from i to r; at i the bordered pit 
is still intact; at k the walls of the lenticular space have been largely dis- 
solved, their inner boundary being marked by a circle; at I one side of 
the bordered pit has been entirely dissolved; at rn and n one sees a series 
of pits which have retained a much-attenuated wall on one side only — ■ 
namely, on that which is provided with the closing membrane. In mak- 
ing the section a crack has been formed in this wall. Between o and r 
both walls of the pits are found to be wholly or partially dissolved, only 
at p and q has the thickened portion of the closing membrane been pre- 
served; at d the spiral structure of both cell-walls is distinctly recogniz- 
able. These walls when united form the common wall of the tracheid; at 
t hyphse are seen traversing the tracheids horizontally. After Hartig. 

entire to toothed; spores subglobose, smooth, deep-ferruginous, 
6-7 jLi; cystidia scanty and short; hyphse deep-ferruginous. 

It causes a disease of oaks. 

P. fruticum B. & C. occurs on living twigs of the orange and 
oleander in Cuba. 



^^ 



X 



y 



THE FUNGI WHICH CAUSE PLANT DISEASE 



423 







Fig. 303. — Polyporus bo- 
rcalis, hymenium with 
sinuous pores. After At- 
kinson. 



P. borealis (Wahl.) Fr."' ^^ 

Pileus sessile, subimbricate, dimidiate to flabelliform, often 
narrowly attached, spongy to corky, very tough, moist and juicy 
when fresh, 5-8 x 8-12 x 2-4 cm.; surface uneven, soft and spongy, 
hirtose-tomentose, azonate, white to yellowish; margin thin, white, 
entire, somewhat discolored on drying: 
context fibrous-coriaceous above, fibrous- 
woody below, white, 0.5-1.5 cm. thick; 
tubes 4-8 mm. long, white to pallid within, 
mouths angular, irregular, somewhat 
radiately elongate, sinuous at times, 1-2 
to a mm., stuffed when young, edges thin, 
white to ochraceous, dentate to lacerate; 
spores ovoid, smooth, hyaline, 5-6 x 3-4 fx; 
hyphae 6-7 fi; cystidia none. 

On pine, spruce, hemlock, balsam pine, 
etc., as a wound parasite or as a sapro- 
phyte on dead trees producing a white rot. The mycelium ad- 
vances longitudinally, radially and tangentially. At certain 
stages it is very abundant and forms cords in the channels formed 
by the fungous enzyme. Later these cords disappear. The young 
mycelium is stout and yellow, later it is more delicate. Dis- 
solution of the cells begins at the lumen 
and proceeds outward, the middle lamella 
persisting last. 
P. dryadeus Fr.^° 

Sporophore very large, sessile, dimidiate, 
rarely circular, usually imbricate, applanate 
or depressed above, convex below, fleshy to 
spongy-corky, rather fragile when dry, 15- 
30 X 25-65 X 3-5 cm.; surface very un- 
even, azonate, opaque, hoary-isabelline, 
anoderm to very thinly encrusted, sub- 
shining and bay; margin thick, pallid, entire to undulate, weep- 
ing; context thick, zonate, subglistening, ferruginous-isabelline to 
fulvous, 2.5-4 cm. thick; tubes grayish-umbrinous to fulvous 
within, 5-15 mm. long, slender, very fragile, mouths whitish when 
young, becoming somewhat resinous in appearance and finally 




Fig. 304. — Polyporus bo- 
realis, hymenium with 
rounded pores. After 
Atkinson. 



424 THE FUNGI WHICH CAUSE PLANT DISEASE 

bay-brown, at first minute, circular, becoming angular, 4 to a 
mm., edges thin, fimbriate to lacerate, deeply splitting and 
separating with age: spores subglobose, smooth, 9-10 x 7-8 /x, 
the outer wall hyaline, the inner membrane brown; cystidia 15- 
35 X 5-9 IX. 

It causes rot of oak wood in America and Europe. 

P. amarus Hedg.*^' ^^^ 

Pileus soft and spongy when young, becoming hard and chalky 
when old, ungulate, often spuriously stipitate from knot-holes, fre- 
quently large, 5-11 x 10-20 x 6-12 cm.; surface pubescent when 
young, rimose and chalky when old, at first buff, becoming tan 
and often blotched with brown when older; margin obtuse, fre- 
quently having an outer band of darker brown, often slightly 
furrowed; context creamy-yellow to tan-colored, usually darker in 
outer layers when old, 4-8 cm. thick; tubes not stratified, brown 
within, cylindric, 0.5-3 cm. in length, shorter next the margin, 
mouths circular or slightly irregular, 1-3 to a mm., yellow-green 
during growth, turning broAvn when bruised or old, becoming 
lacerate; spores hyaline or slightly tinged with brown, smooth, 
ovoid, 3^ x 5-8 n, nucleated; cystidia none. 

The cause of "pin rot" or peckiness of incense cedar. 

P. schweinitzii Fr.^^' ^^ 

Pileus spongy, circular, varying to dimidiate or irregular, 15-20 
cm. broad, 0.5-2 cm. thick; surface setose-hispid to strigose- 
tomentose and scrupose in zones, ochraceous-ferruginous to ful- 
vous-castaneous or darker, quite uneven, somewhat sulcate, ob- 
scurely zonate; margin yellow, rather thick, sterile: context very 
soft and spongy, fragile when dry, sometimes indurate with age, 
flavous-ferruginous to fulvous, 0.3-0.7 mm. thick; tubes short, 
2-5 mm. long, flavous within, mouths large, irregular, averaging 
1 mm. in diameter, edges thin, becoming lacerate, ochraceous- 
olivaceous to fuliginous, rose-tinted when young and fresh, quickly 
changing to dark-red when bruised : spores ovoid, hyaline 7-8 x 3-4 
jjl: stipe central to lateral or obsolete, very irregular, tubercular 
or very short, resembling the pileus in surface and substance. 

On coniferous trees especially spruce, fir, pine, larch, arbor \dta3, 
entering through the root system and extending up the trunk, 
causing heart-rot. The tracheids exhibit spiral cracks and fissures 



THE FUNGI WHICH CAUSE PLANT DISEASE 



425 



due to the shrinking of the walls. Fig. 289. Diseased wood is 
yellowisli and of cheesy consistency; brittle when dry. 

P. betulinus (Bui.) Fr.^^- ss 

Pileus fleshy to corky, compressed-ungulate, convex above, 




plane below, attached by a short umbo behind, varying to bell- 
shaped when hanging from horizontal trunks, 5-30 x 5-20 x 2-5 
cm.; surface smoky, covered with a thin, separating pellicle, 
glabrous, devoid of markings, cracking with age; margin velvety, 
concolorous, obtuse, projecting nearly a centimeter beyond the 



426 THE FUNGI WHICH CAUSE PLANT DISEASE 

hymenium: context fleshy-tough, elastic, homogeneous, 3 cm. thick, 
milk-white; tubes 0.5 cm. long, 2-3 to a mm., sodden-white, sepa- 
rated from the context by a thin pink layer; mouths very irregular, 
dissepiments thicker than the pores, obtuse, entire, crumbling 
away in age, leaving the smooth, white context; spores white, 
cylindrical, curved, 4-5 m in length. The mycelium penetrates 
lignified cell walls entering the living cells and causing death. 

On birch it causes a decay of the sap wood similar to that caused 
by Femes fomentarius. 

P.adustus (Wild.) Fr. is a common saprophyte of deciduous trees. 

Polystictus Fries (p. 417) 

Sporophore leathery, usually thin; pores developing from the 
center to the circumference of the hymenophore. The thicker 
forms are cjuite close to some species of Polyporus. 

About four hundred fifty species. 

P. versicolor (L.) Fr.^^' ^^ 

Pileus densely imbricate, very thin, sessile, dimidiate, conchate, 
2-4 X 3-7 X 0.1-0.2 cm.; surface smooth, velvety, shining, marked 
with conspicuous, glabrous zones of various colors, mostly laterice- 
ous, bay or black; margin thin, sterile, entire; context thin, mem- 
branous, fibrous, white; tubes punctiform, less than 1 mm. long, 
white to isabelline within, mouths circular to angular, regular, 
even, 4-5 to a mm., edges thick and entire, becoming thin and 
dentate, white, glistening, at length opaque-isabelline or slightly 
umbrinous: spores allantoid, smooth, hyaline, 4-6 x 1-2 n; 
hyphse 2-6 /x; C3^stidia none. 

Von Schrenk regards this as strictly a saprophyte except when 
on catalpa, where it causes a heart-rot. It is common on almost 
any kind of wood. 

Catalpa wood under its action becomes straw-colored and finally 
soft and pithy. Both cellulose and lignin are dissolved. 

P. sanguineus (L.) Fr. & P. cinnabarinus (Jacq.) Fr. are sapro- 
phytes on dead parts of live trees. 

P. velutinus (Pers.) Fr. is a common saprophyte which is perhaps 
sometimes parasitic. 

P. occidentalis Klachb. is recorded as a parasite on Pterocarpus 
indicus in the Malay peninsula.^^ 



v 

"•mi 



THE FUNGI WHICH CAUSE PLANT DISEASE 



427 




P. pergamenus Fr.^^ 

Pileus exceedingly variable, sessile or affixed by a short tubercle, 
dimidiate to flabelliform, broadly or narrowly attached, 2-5 x 2-6 
X 0.1-0.3 cm.; surface finely villose-tomentose, smooth, white 
or slightly yellowish, 
marked with a few nar- 
row indistinct laterice- 
ous or bay zones; mar- 
gin thin, sterile, entire to 
lobed; context very thin, 
white, fibrous; tubes 1- 

3 mm, long, white to dis- 
colored within, mouths 
angular, somewhat irreg- 
ular, 3-4 to a mm., 
usually becoming irpici- 
form at an early stage, 
edges acute, dentate, be- 
coming lacerate, white to 
yellowish or umbrinous : 
spores smooth, hyaline. 

It causes a sap wood rot of practically all species of deciduous 
trees, often on dead trees, less frequently on living trees which 
have been severely injured. In general the rotten wood resembles 
that produced by P. versicolor; microscopically it is seen that 
the fungus attacks chiefly the lignin. 

P. hirsutus Fr. 

Pileus confluent-effused, more or less imbricate, sessile, dimi- 
diate, applanate, corky-leathery, rather thick, flexible or rigid, 
3-5 X 5-8 X 0.3-0.8 cm. ; surface conspicuously hirsute, isabelline to 
cinereous, concentrically furrowed and zoned; margin at length 
thin, often fuliginous, sterile, finely strigose-tomentose, entire or 
undulate: context white, thin, fibrous, spongy above, 1^ mm. 
thick; tubes white, 1-2 mm. long, mouths circular to angular, 

4 to a mm., quite regular, edges thin, firm, tough, entire, white 
to yellowish or uml^rinous; spores smooth, hyaline, cylindrical, 
slightly curved, 2.5-3 ^l. 

It is a wound parasite of the Mountain Ash.^^ 



Fig. 306. 



-Polystictus pergamenus. After 
Clements. 



428 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Fomes Fries (p. 417) 

Sporophore sessile, ungulate or applanate; surface varnished, 
encrusted, sulcate, vinose, or anoderm, rarely zonate; context 
corky to punky; tubes cylindric, stratiose; spores smooth, hyaline 
or brown. 

A genus of some three hundred species. 

■n • • • /T \ r^-u 65, 67, 78, 79 

F. igniarius (L.) Gill. ' ' ' 

Pileus woody, ungulate, sessile, 6-7 x 8-10 x 5-12 cm.; surface 
smooth, encrusted, opaque, velvety to glabrous, ferruginous to 




Fig. 307. — Fuuica igaiuriuti, frum maple. After Atkinson. 

fuscous, becoming rimose with age; margin obtuse, sterile, fer- 
ruginous to hoary, tomentose; context woody, distinctly zonate, 
ferruginous to fulvous, 2-3 cm. thick; tubes evenly stratified, 
2-4 mm. long each season, fulvous, whitish-stuffed in age, mouths 
circular, minute, 3-4 to a mm., edges obtuse, ferruginous to ful- 
vous, hoary when young: spores globose, smooth, hyaline, 6-7 n; 
spines 10-25 x 5-6 /i. 

It is the cause of a white heart-rot, is one of the most widely 
distributed forms of wound parasites and occurs on more species 
of broad-leaf trees than any other similar fungus. Among its 
hosts are beech, oak, apple, peach, willow, aspen, the maples, birch, 
butternut, walnut, oak, hickory, alder. 

The first sporophores usually appear at the point of initial 



THE FUNGI WHICH CAUSE PLANT DISEASE 



429 



infection. The mycelium grows mainly in the heart wood Ijut it 
may gain entrance through the sap wood or encroach upon the 
sap wood from the heart wood. Its growth may continue after 
the death of the host. In early stages it follows the medullary 



HSPw'^-'^' 










i 





Fig. 308. — A dead beech tree with sporophores of F. fomenta- 
rius. After voq Schrenk and Spaulding. 

rays. The completely rotted wood is white to light yellow and in 
it the mycelium abounds in the large vessels and the medullary 
rays. The walls of the affected wood cells are thin and the middle 
lamella is often wholly lacking, due to solution of the lignin. 

F. fomentarius (L.) Fr."' " 

Pileus hard, Avoody, ungulate, concave below, 7-9 x 8-10 x 3-10 
cm. ; surface finely tomentose to glabrous, isabelline to avellaneous 



430 THE FUNGI WHICH CAUSE PLANT DISEASE 

and finally black and shining with age, zonate, sulcate, horny- 
encrusted; margin obtuse, velvety, isabelline to fulvous; context 
punky, homogeneous, ferruginous to fulvous, conidia-bearing, 
3-5 mm. thick; tubes indistinctly stratified, not separated by lay- 
ers of context, 3-5 mm. long each season, avellaneous to umbrinous 
within, mouths circular, whitish-stuffed when young, 3-4 to a mm. ; 
edges obtuse, entire, grayish-white to avellaneous, turning dark 
when bruised: spores globose, smooth, very light brown, 3-4 ju; 
hyphse brown, 7-8 m; cystidia none. 

The mycelium kills the cambium and causes a white rot of the 
sap wood of deciduous trees, especially beech, birch, elm, maple. 
The wholly rotted wood is soft, and spongy, light yellow and 
crumbles into its separate fibers. 

F. everhartii (E. & G.) ''^' ^'' ( = Pyropolyporus prserimosa). 

Pileus woody, dimidiate, ungulate, broadly attached behind, 
6-10 X 6-15 X 3-8 cm. ; surface glabrous, slightly encrusted, deeply 
sulcate, not polished, gray to brownish-black, slightly rimose 
in age; margin obtuse, covered with ferruginous tomentum, be- 
coming gray and glabrous: context corky to woody, repeatedly 
zoned, fulvous in dried specimens, 2-3 cm. thick; tubes evenly 
stratified, 0.5-1 cm. long each season, fulvous, mouths circular, 
4 to a mm., edges rather thin, entire, ferruginous to fulvous, 
glistening, the hymenium becoming much cracked in age: spores 
globose, smooth, ferruginous, 3-4.5 fx; spines abundant, pointed, 
larger at the base, 15-25 x 6-10 ij.. 

On black oaks, and walnuts causing a rot almost indistin- 
guishable from that caused by F. igniarius. The mycelium 
often grows into the living sap wood. 

F. carneus Nees.^^' ^^ 

Pileus woody, dimidiate, varying from cohchate to ungulate 
often imbricate and longitudinally effused, 2-4 x 6-8 x. 0.5-3 cm.; 
surface rugose, subfasciate, slightly sulcate, rosy or flesh-colored, 
becoming gray or black with age; margin acute, becoming obtuse, 
sterile, pallid, often undulate; context floccose-fibrose to corky, 
rose-colored, 0.2-2 cm. thick; tubes indistinctly stratose, 1-2 mm. 
long each season, mouths circular, 3-4 to a mm., edges obtuse, 
concolorous; spores ellipsoid, smooth, thick-walled, subhyaline, 
3.5 X 6 ju. 



V 



THE FUNGI WHICH CAUSE PLANT DISEASE 431 

On red cedar and arljor vita causing pockets, also on dead 
spruce and fir. The cellulose is almost all removed from the 
affected cells of the heart wood. The mycelium is scant and when 
young is pale and with numerous clamps. It extends horizontally 
through the tracheids, giving off lateral branches. None is found 
in the sap wood. 

F. annosus (Fr.) Cke.^^'^^^ ( = Trametes, radiciperda R. Hartig). 

Pileus woody, dimidiate, very irregular, conchate to applanate, 
10-13 X 5-8 X 0.5-2 cm.; surface at first velvety, rugose, anoderm, 
light brown, becoming thinly encrusted, zonate, and finally black 
with age; margin pallid, acute, becoming thicker; context soft- 
corky to woody, white, 0.3-0.5 cm. thick; tubes unevenly stratified, 
2-8 mm. long each season, white, mouths subcircular to irregular, 
3-4 to a mm., edges rather thin, entire, firm, white, unchanging: 
spores subglobose or ellipsoid, smooth, hyaline, 5-6 x 4-5 m- 

On pine, fir and various deciduous trees, described by Hartig^^ 
as the most dangerous of all conifer parasites. It is not so plentiful 
in America as in Europe. 

The sporophores appear near or on the roots, between the 
bark scales, where the white felted delicate mycelium also occurs. 
The spores, carried presumably by rodents, germinate upon the 
bark of roots; the mycelium penetrates to the living cortex, forces 
its way into the wood and follows up the stem and doAMi the root. 
The parenchyma cells are killed and browned; the wood becomes 
violet, later brownish-yellow. The hypha? travel in the cell- 
lumen and pierce the walls. The lignified parts are dissolved 
first, later the middle lamella disappears. Eventually the whole 
root system may become involved and the death of the tree result. 

F. juniperinus (v. Sch.) S. & Sy.^^ 

Pileus woody, ungulate, 3-5 x 5-8 x 5-7 cm. ; surface tomentose, 
deeply sulcate, ferruginous to gray, at length rough and grayish- 
black; margin obtuse, velvety, melleous or ferruginous to hoary: 
context corky to woody, reddish-fulvous, 0.5-1 cm. thick; tubes 
indistinctly stratified, 0.5-1 cm. long each season, melleous within, 
reddish-fulvous in the older layers, mouths circular to angular, 
2-3 to a mm., edges rather, thin, entire, even, melleous: spores 
reddish-brown, smooth; spines blunt, only slightly projecting. 
On red cedar. 



432 THE FUNGI WHICH CAUSE PLANT DISEASE 

In the holes caused by the fungus in the heart-wood is found 
a velvety mass of reddish-yellow mycelium, glistening with color- 
less liquid and holding masses of reddish-brown wood fiber. Long 
white fibers of cellulose with the lignin removed project into the 
cavities from the ends. 

Structural change begins soon after the mycelium enters a 
cell lumen. The primary lamella becomes granular and is dissolved 
by a lignin-splitting enzyme, the secondary lamella becomes white 
and the cells fall apart. 

The mycelium in newly invaded tissue is nearly hyaline and 
extends lengthwise. Within the tracheids branches are given off 
in all directions. 

The sporophore appears after decomposition is considerably 
advanced. 

F. laracis (Jacq.) Murr.^^^ 

Pileus firm, at length fragile, ungulate to cylindical, 3-8 x 5-10 
X 4-20 cm.; surface anoderm, powdery, white or slightly yellow- 
ish, concentrically sulcate, becoming slightly encrusted, tuberculose 
and rimose; margin obtuse, concolorous: context soft, tough, at 
length friable, chalk-white or slightly yellowish, very bitter, 
with the odor of fresh meal, 1-3 cm. thick; tubes evenly strati- 
fied, concolorous, 5-10 mm. long each season, mouths circular to 
angular, 3-4 to a mm., edges thin, fragile, white, becoming dis- 
colored and lacerate, wearing away with age : spores ovoid, smooth, 
hyaline, 4-5 fx; hypha? 5 /x; cystidia none. 

A wound parasite of the larch, pine and spruce in Europe and 
America. 

F. ribis (Schw.) Gill.^^ 

Pileus tough, corky, Ijccoming rigid, conchate, laterally connate, 
3-5 X 5 10 X 0.7-1.5 cm.; surface rough, velvety, anoderm, in- 
distinctly zoned, ferruginous to umbrinous, becoming glabrous 
and slightly encrusted with age; margin undulate to lobed, fer- 
ruginous, furrowed: context punky, fulvous, 3-5 mm. thick; 
tubes indistinctly stratified, 1-2 mm. long each season, fulvous, 
mouths circular, 5-6 to a mm., edges rather thin, entire, ferruginous 
to fulvous, hoary when young: spores globose or subglobose, 
pale yellowish-brown, smooth, 3-4 x 3 /z; hyphse 2.5 fx; cystidia 
none. 



THE FUNGI WHICH CAUSE PLvVNT DISEASE 433 

This is ;i wound parasite on the heart wood of sassafras and is 
also found on roots and stems of various shrubby plants including 
rose, goosel)erry and currant. The fungus fills the large vessels 
and tracheids with a brown mycelium and dissolves the entire 
wall locally. 

F. fulvus (Scop) Gill5 

Pileus woody, triquetrous, rarely ungulate, thick and broadly 
attached behind, 1-3 x. 5-7 x 3-8 cm.; surface smooth, very 
slightly sulcate, velvety, ferruginous, becoming horny and 
glabrous and finally nearly black with age; margin subobtuse, 
ferruginous, velvety; context woody, fulvous, 1-2 cm. thick; 
tubes evenly stratified, 2-3 mm. long each season, fulvous, mouths 
circular, 3 to a mm., edges obtuse, entire, ferruginous to fulvous; 
spores globose, compressed on one side, hyaline, 5.5-6 x 4.5-5 /x; 
spines fulvous, 15-20 x 7-0 m; hyphffi 2.5 n. 

On plum, birch and other trees. 

The decayed wood is red-brown and crumbles when crushed. 

F. fulvus oleae Lin.^' is injurious on olive in Italy. 

F. nigricans Fr.^"' '■'° is very similar to F. igniarius from which it 
differs chiefly in the black upper surface and the bluish or blackish 
hymenial surface of the sporophores. Murrill ^^ regards it as a 
variety of F. igniarius. 

As a wound parasite it causes a reddish-brown heart-rot of 
deciduous trees, especially of willow, birch, poplar, beech. 

F. lucidus (Fr.) Bon. causes a cocoanut root-rot. 

F. fraxinophilus (Pk.) Sacc^'- ^^ 

Pileus woody, subtriangular, compressed-ungulate, usually 
decurrent, 5-10 x 6-12 x 2-4 cm.; surface white, pulverulent or 
finely tomentose, concentrically sulcate, becoming gray or black 
and rimose with age; margin tumid, white or yellowish, velvety to 
the touch; context corky to woody, zonate, isabelline, 0.5-1 cm. 
thick; tubes evenly but indistinctly stratified, 2-4 mm. long each 
season, white when young, concolorous with the context in the 
older layers, mouths white, subcircular, 2 to a mm., edges obtuse; 
spores broadly ellipsoid, smooth, hyaline, thin-walled, 6-7 x 7-8 
ju; hyphse light yellowish-brown, 10-12 n; cystidia none. 

It causes a heart-rot of trunk and branches of species of ash. 

The starch in the host cells is lost early by diastatic action in 



434 THE FUNGI WHICH CAUSE PLANT DISEASE 

advance of the fungus, the nearest hj^phse of which may be several 
millimeters distant, and is replaced by a decomposition product. 
The mycelium advances through the medullary rays and spreads 
through spring and summer bands, abstracting the lignin; the 
middle lamella dissolves and the cells fall apart. Completely 
rotted wood is straw-colored, very soft, non-resistant. The young 
hyphse are very fine and require an immersion less for observation. 
Clamp connections are frequent. The sporophore appears after 
the destruction of the wood is considerably advanced. 

F. hartigii All. is very similar to, if not identical with, 
F. igniarius. 

It produces a white rot of firs and spruces. The mycelium is 
yellowish with numerous branches which may fill the cavities of 
the bordered pits of the tracheids. The middle lamella is even- 
tually dissolved, later the inner walls. 

F. robiniae (Murr.) S. & Sy. ''' '^ 

A large fungus with dark rimose surface and tawny hymenium. 
Pileus hard, woody, dimidiate, ungulate to applanate, 5-25 x 5-50 
X 2-12 cm.; surface velvet}^ smooth, soon becoming very rimose 
and roughened, fulvous to purplish-black, at length dull-black, 
deeply and broadly concentrically sulcate; margin rounded, 
velvety, fulvous; context hard, woody, concentrically banded, 
1-3 cm. thick, fulvous; tubes stratose, 0.15-0.5 cm. long, 50 a 
mm., fulvous, mouths subcircular, edges entire, equaling the 
tubes in thickness: spores subglobose, smooth, thin-walled, fer- 
ruginous, copious, 4-5 fx; cystidia none. 

On black locust causing heart-rot, arising from wound infection 
of living trees. The very hard wood becomes a soft, yellow to 
brown mass, spongy when wet. The decay extends out in radical 
lines from the center, along the large medullary rays, killing the 
cambium and bark on reaching them. The lignin is first dissolved, 
later the cellulose. 

The fungus ceases growth on the death of its host. 

F. marmoratus Berk! (=F. fasciatus [Sw.] Cooke.) 

Pileus hard, woody, dimidiate, applanate to ungulate, convex 
above, 7-10 x 8-15 x 2-6 cm.; surface finely tomentose, at length 
glabrous, concentrically sulcate, at first mole-colored, changing 
to umbrinous, and finally avellaneous with black fasciations; 



THE FUNGI WHICH CAUSE PLANT DISEASE 



435 



margin acute to obtuse, isabelline, sterile, undulate or entire; 
context punky, thin, ferruginous to fulvous, zonate, 3-5 mm. 
thick, tubes indistinctly stratified, 5-10 mm. long each season, 
avellaneous within, mouths circular, minute, 4-5 to a mm. edges 
obtuse avellaneous to umbrinous, becoming darker when bruised: 
spores subglobose, smooth, light brown, 5-7 ix; hyphae brown, 4-6/i; 
cystidia none. 

On water oak and orange in Florida,^'* especially abundant on 
the former. 

F. sessilis (Murr.) Sacc. 

A variable fungus with wrinkled varnished cap and acute margin, 
found on decaying deciduous trees. Pileus corky to woody, dimidi- 
ate, sessile or stipitate, imbricate or connate at times, conchate 
to fan-shaped, thickest behind, thin at the margin, 5 15 x 7-25 
X 1-3 cm.; surface glabrous, 
laccate, shining, radiate- 
rugose, concentrically sul- 
cate, yellow to reddish- 
chestnut, at length opaque, 
dark-brown usually marked 
near the margin with alter- 
nating bay and tawny 
zones; margin usually very 
thin and acute, often curved 
downward, often undulate, 
rarely becoming truncate, 
white, at length concolorous : 
context soft-corky or woody, 
radiate-fibrous, concentri- 
cally banded, ochraceous- 
fulvous; tubes 0.52 cm. 
long, 3-5 to a mm., brown 
within, mouths circular or 
angular, white or grayish-brown, edges thin, entire: spores ovoid, 
obtuse at the summit, attenuate and truncate at the base, verru- 
cose, yellowish-broAvn, 9-11 x 6-8 m; stipe laterally attached, 
usually ascending, irregularly cylindrical, 1-4 x 0.5-1.5 cm., re- 
sembling the pileus in color, surface and substance, often obsolete. 




Fr;. 309. — F. pinicola growing on tlcafl trunk 
of western hemlock. After von 8chrenk. 



436 THE FUNGI WHICH CAUSE PLANT DISEASE 

It occurs on oak and maple ®^ as a wound parasite, destroying 
bark and cambium. This and related species are usually 
saprophytic. 

F. pinicola (Fr.) Cke.^^ 

Pileus corky to woody, ungulate, 8-15 x 12-40 x 6-10 cm.; 
surface glabrous, sulcate, reddish-brown to gray or black, often 
resinous; margin at first acute to tumid, pallid, becoming yellowish 
or reddish-chestnut: context woody, pallid, 0.5-1 cm. thick; tubes 
distinctly stratified, 3-5 mm. long each season, white to isabelline, 




Fig. 310. — Fomes applanatus. After Clements. 



mouths circular, 3-5 to a mm., edges obtuse, white to cream-colored; 
spores ovoid, smooth, hyaline, 6 ix; hyphse 8 m; cystidia none. 

It occurs on conifers; pine, hemlock, spruce, balsam, larch, etc., 
more rarely on beech, birch and maple, as a wound parasite of 
the heart wood. The sporophores are often absent until after 
death of the host. The tracheids bear many holes. The wood 
carbonizes, the cellulose is destroyed and sheets of mycelium form, 
particularly within the space occupied by the medullary rays and 
in tangential crevices. ' " Fig. 309. 

F. applanatus (Pers.) Wallr. 

Pileus hard, woody, dimidiate, applanate, 6-15 x 8-30 x 1-4 cm.; 
surface milk-white to gray or umbrinous, glabrous, concentrically 
sulcate, encrusted, fasciate with obscure lines, condia-bearing, 



THE FUNGI WHICH CAUSE PLANT DISEASE 437 

usuall}'^ brownish during the growing season from the covering of 
conidia; margin ol)tuse, broadly sterile, white or slightly cremeous, 
entire to undulate: context corky, usually rather hard, zonate, 
fulvous to bay, 5-lQ mm. thick, thinner with age; tubes very 
evenly stratified, separated l)y thin layers of context, 5-10 mm. 
long each season, avellaneous to uml^rinous within, mouths circular, 
5 to a mm., whitish-stuffed when young, edges obtuse, entire, 
white or slightly yellowish to umbrinous, quickly changing color 
when bruised: spores ovoid, smooth or very slightly roughened, 
pale yellowish-brown, truncate at the base, 7-8 x 5-6 /x. 

It is described by Heald ^'^ as the cause of rot of both heart and 
sap wood of living cotton-wood trees. The invaded medullary 
rays first lose their starch by digestion. Next the lignin is dis- 
solved, then the cellulose. 

Von Schrenk regards this fungus as a saprophyte since it grows 
usually only on outer sap wood that is dead and so far as he ob- 
served, it does not cause a true disease. 

F. ulmarius Fr. is injurious to elm. 

F. semitosus Berk, causes root rot of Hevea in India. 

F. australis Fr. is a wound parasite on Acacia in Ceylon. 

Trametes Fries (p. 417) 

Sporophore annual, rarely perennial, sessile; context homo- 
geneous, coriaceous to corky, extending between the tubes, which 
are circular or irregular. 

There are about one hundred forty-five species. 

T' • : /T-iU \ 17 56, 74, 78, 79 

T. pmi (Thore) Fr. ' ' ' 

Pileus hard, woody, typically ungulate, conchate or effused- 
reflexed in varieties, often imbricate, 5-8 x 7-12 x 5-8 cm., smaller 
in varieties; surface very rough, deeply sulcate, tomentose, tawny- 
brown, becoming rimose and almost black with age; margin rounded 
or acute, tomentose, ferruginous to tawny-cinnamon, entire, 
sterile in large specimens: context soft-corky to indurate, homo- 
geneous, ferruginous, 5-10 mm. thick, thinner in small specimens; 
tubes stratified, white to avellaneous within, becoming ferrugi- 
nous at maturity and in the older layers, 5 mm. long each season, 
much shorter in thin specimens, mouths irregular, circular or 
daedaleoid, often radially elongate, averaging 1 to a mm., edges 



138 



THE FUNGI WHICH CAUSE PLANT DISEASE 



ferruginous to grayish-umbrinous, glistening when young, rather 
thin, entire; spores subglobose, smooth, hyaline at maturity, 
becoming brownish with age, 5-6 x 3-4 ju; spines abundant, short, 
25-35 X 4-6 /x. 

It occurs on pine, spruce, larch, hemlock, and fir as a wound 
parasite of the heart wood; it is also on willow in Europe and 
America. 

The spores are wind-borne and, lodging on unprotected sur- 
faces, develop a mycelium which grows both up and down, spread- 
ing most rapidly in a longitudinal direction, or horizontally follow- 
ing an annual ring. The fungous enzyme first dissolves the lignin 
leaving the individual tracheids free and of nearly pure cellulose. 
The cellulose is later dissolved, resulting in holes in the wood. 
It is found on most of the conifers of the United States as a sapro- 
phyte. The wood becomes white-spotted. In late stages of decay 
the entire wood is full of small holes which are lined with a white 
fungous felt. 

T. ribinophila Murr. is perhaps a parasite on the black locust. 

T. theae Zimm. cause a root- 
rot of tea in India.^^ 
T. suaveolens (L.) Fr. 
Pileus large, subimbricate, 
dimidiate, sessile, convex above, 
plane or concave below, 4-6 x 
5-12 X 1-3 cm.; surface smooth, 
anoderm, azonate, finely villose- 
tomentose to nearly glabrous, 
white to pale-isabelline; margin 
thick, sterile, entire: context 
white, punky-corky, 1-2 cm. 
thick, very fragrant when fresh, 
with the odor of anise; tubes 5- 
15 mm. long, white within, 
mouths circular, 2 to a mm., edges at first very thick, white, entire, 
becoming thinner and often blackish with age : spores oblong-ovoid, 
subsinuate, smooth, hyaline, 8-9 x 3-5 fx; hyphse 7 ju; cystidia 
none. 

On willow. 




Fig. 311. — Favolus europseus. 
After Lloyd. 



THE FUNGI WHICH CAUSE PLAxNT DISEASE 439 



Favolus Fries (p. 417) 

Sporophore leathery, fleshy, or coriaceous, laterally stipitate; 
hymeiiium with large elongated pores which may even become 
lamellate, Fig. 311. 

A genus of some seventy species. 

F. europaeus Fr. is a European parasite of fruit and nut trees ; it 
is also common in America. 

Daedalea Persoon (p. 417) 

Hymenophore epixylous, usually large and annual, sessile, 
applanate to ungulate; surface anoderm, glabrous, often zonate: 
context white, wood-colored or brown, rigid, woody, tough or 
punky: hymenium normally labyrinthiform, but varying to lamel- 
late and porose in some species: spores smooth, hyaline. 

About seventy-six species. Fig. 312. 

D. quercina (L.) Pers. 

Pileus corky, rigid, dimidiate, sessile, imbricate, applanate, 
convex below, triangular in section, 6-12 x 9-20 x 2-4 cm.; surface 
isabelline-avellaneous to cinereous or smoky-black with age, 
slightly sulcate, zonate at times, tuberculose to coUiculose in the 
older portions; margin usually thin, pallid, glabrous; context 
isabelUne, soft-corky, homogeneous, 5-7 mm. thick; tubes laby- 
rinthiform, becoming nearly lamellate with age in some specimens, 
1-2 cm. long, 1-2 mm. broad, chalk-white or discolored within, 
edges obtuse, entire, ochraceous to avellaneous. 

Common on oak and chestnut, often on living trees but 
growing only on the dead wood. 

Lenzites Fries (p. 417) 

Hymenophore small, annual, epixylous, sessile, conchate; 
surface anoderm, usually zonate and tomentose: context white or 
brown, coriaceous, flexible; hymenium lamellate, the radiating 
gill-like dissepiments connected transversely at times, especially 
when young: spores smooth, hyaline. Fig. 313. 

About seventy-five species. 



440 



THE FUNGI WHICH CAUSE PLANT DISEASE 



L. abietina (Bui.) Fr. occurs on firs, L. sepiaria (Wulf.) Fr. 
has been reported as a parasite on pine, spruce, etc., but recent 
work of Spaulding ^^ shows it to be merely a saprophyte. L. cor- 
rugata Klot, L. vialis Pk. and L. betulina (L.) Fr. are common 




Fig. 312. — Daedalea quercina on oak. After von ydircnk unci Spaulding. 

saprophytes on deciduous trees; perhaps also parasitic; L. varie- 
gata Fr. on beech and poplar. 

Boletaceae (p. 402) 

Sporophores fleshy, capitate, centrally or laterally stipitate, 
rarely actually sessile; hymenium on the under surface only, of 
tubes which separate readily from the pileus and are united to 
each other or only closely approximated. 

A family of less than three hundred species. 

Key to Genera op Boletaceae 

Pores adnate to each other I. Boletineae. 

Pores separate tubes II. Fistulineae. 

Sporophore more or less fleshy 1. Fistulina, p. 441. 

Sporophore leathery 

Tubes with a central papilla 2. Theleporus. 

Tubes without papillae 3. Porothelium. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



441 



Fistulina Buller (p. 440) 

Sporophore fleshy, laterally short-stipitate, hymenial sur- 
face at first granular, then each granule becoming a tube; these 
are approximate but not united; spores brown in mass. Fig. 314. 

A genus of a half dozen species. 




Fig. 313. — Lcnzites betulina. After Clements. 

F. hepatica (Scha.) Fr. 

' Cap 8-20 cm. wide, bright-red or red-brown, liver-shaped to 
shelf-like, more or less lobed, smooth, more or less sticky when 
wet; flesh containing reddish fibers; stem short, lateral and almost 
wanting, or sometimes long excentric; tubes pale to yellowish or 



442 



THE FUNGI WHICH CAUSE PLANT DISEASE 



pinkish; spores yellowish to pinkish, ellipsoid, 5-7 x 3-4 ju. 
It is found on oak and chestnut. 



Agaricacese (p. 402)^^ 

Sporophore usually fleshy, rarely coriaceous or leathery, stip- 
itate or shelving; stipe variable in development, lateral or central, 




Fig. 314.— Fistulina hepatica. After Clements. 

annulate or not, the entire young sporophore often volvate at 
first; hymenium lamellate, the lamellae usually free, rarely anas- 
tomosing, sometimes dichotomous, rarely reduced to ridges or 
slight folds. 

A family of over twelve hundred species. 

Key to Tribes of Agaricaceae 

Hymenium with the lamellae ridge or fold- 
like, imperfectly developed I. Cantharellese, p. 443. 

Hymenium with normally developed gills 
Lamellae sometimes anastomosing, and 

forming meshes IL Paxilleae. 

Lamellae not anastomosing 

Lamellse and often the cap deliquescent 

(in Montagnites withering,) IIL Coprineae. 

Lamellae not deliquescent 

Lamellse thick and fleshy, becoming 

waxy IV. Hygrophoreae. 



THE FUNGI WHICH CAUSE PLANT DISEASE 443 

Lamellse not fleshy or waxy 
Substance of the pileus of two 
kinds of hyphse, one thick, 
tubular and in bundles, the 
other thin, single and fre- 
quently lactiferous V. Lactariese. 

Substance of the pileus of only one 

kind of hyphse 

Sporophore at maturity leathery 

or corky, persistent, rarely 

fleshy 

Lamellae at maturity split 

lengthwise VI. Schizophylleae, p. 444. 

Lamellae at maturity not 

splitting VII. Merasmieae, p. 445. 

Sporophore at maturity fleshy, 

finally putrescent VIII. Agariceae, p. 448. 

Cantharelleae (p. 442) 

This tribe is characterized l^y its low ridge or fold-like lamellae. 
The hj^menial characters indicate an approach to the Thelephora- 
ceae. 

Key to Genera of Cantharelleae 

Hymenium on the upper side of the pileus. I. Rimbachia. 
Hymenium on the under side of the pileus. 
Hymenium with thin veins 

Veins anastomosing 2. Campanella. 

Veins not anastomosing 3. Arrhenia. 

Hymenium with thick folds 

Substance of the pileus leathery, 

tough 4. Trogia, p. 444. 

Substance of the pileus thin, soft- 
leathery 
Sporophore sessile, at first saucer- 
shaped 5. Leptopus. 

Sporophore laterally stalked, fan- 
shaped 6. Leptoglossum. 

Substance of the pileus fleshy 7. Cantharellus. 



^' 



444 



THE FUNGI WHICH CAUSE PLANT DISEASE 




Fig. 315. — Trogia faginea. 
After Hennings. 



Trogia Fries (p. 443) 

Cap thin, leathery, or membranous, persistent, sessile, irreg- 
ular; hymenium of branched 
folds, the branches chiefly mar- 
ginal. 

There are some seven species. 
T. faginea. (Schr.) v. Sch. 
Sporophore 1-2 cm. broad, 
beaker-formed or irregular mar- 
gined; yellow or orange without, 
rarely whitish, with fine hairs; 
ribs concolorous, dichotomous; spores cylindric, 4 x 1-1.5 m, 
smooth, colorless. 

It injures birch, beech, hazel, etc. 

Schizophylleae (p. 443) 

Sporophore, leathery, persistent, the cleft gills with recurved 
margins. A group of but four genera and less than a score of 
species. 

Key to Genera of Schizophylleae 

Sporophore leathery, sessile 1. Schizophyllum, p. 444. 

Sporophore fleshy or membranous, stipitate 
Stipe central 

Cap thin, membranous 2. Rhacophyllus. 

Cap fleshy 4. CEdemansiella. 

Stipe lateral 3. Pterophyllus. 

Schizophyllum Fries 

Cap woolly, upturned, sessile, epixylous; gills cleft, the mar- 
gins recoiled; texture leathery. 

About twelve species. Fig. 316. 

S. alneum (L.) Schr. 

Cap 1-4 cm. wide, white or gray-woolly, upturned, attached 
excentrically, irregularly saucer-shaped* stem lacking; gills grayish 
to purplish; spores subglol^ose, 2-3 /x. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



It parasitizes sugar cane, horse chestnut, chestnut, mulberry 
and orange. 



445 

22 




Fig. 31G. — S. alneum. After Clements. 



Marasmieae (p. 443) 

Pileus tough, leathery, thin, membranous, or rarely somewhat 
fleshy, reviving after drying with the return of moisture. 
About five hundred fifty species. 

Key to Genera of Marasmieae 

Gills leathery-horny; spores black 1. Anthracophyllum. 

Gills leathery; spores hyaline 

Pileus not distinct from the stipe; sporo- 
phore trumpet-shaped 

Gills forked, edge blunt 2. Xerotus. 

Gills with a thin edge 

Gills toothed on the margin , 3. Lentinus, p. 445. 

Gills with an even margin 4. Panus, p. 446. 

Pileus distinct from the stipe 
Annulus wanting 

Pileus firm and dry 5. Marasmius, p. 446. 

Pileus somewhat gelatinous 6. Heliomyces. 

Annulus present 7. Merasmiopsis. 

Lentinus Fries 

Sporophore trumpet-shaped, pileus and stipe not distinct, 
leathery, pileus central or lateral, gills toothed; spores white. 
About three hundred forty species. 



446 



THE FUNGI WHICH CAUSE PLANT DISEASE 



L. conchatus (Bui.) Schr. is found on birch, poplar, aspen. 
L. lepideus ^^^ Fr. on pine, birch, etc. 




Fiu. 317. — Lentinus lepideus. After Clements. 



Panus Fries (p. 445) 

This genus is very close to Lentinus from which it is separated 
by the character of the gills which have an entire edge. 
P. stipicus (Bui.) Fr. is perhaps parasitic occasionally. ^°° 

Marasmius Fries (p. 445) 

Sporophore tough, withering, often reviving in renewed moisture; 
pileus, with few exceptions, regular, thin, leathery, without a veil, 
sharply cUfferentiated from the stipe, rarely sessile or laterally 
attached; stipe tough, cartilaginous or horny, without an annulus; 
gills tough, thin, leathery or membranous, entire margined. 

Some four hundred fifty species of wide distribution, but chiefly 
small tropical fungi. 



.j»%-.^ 



THE FUNGI WHICH CAUSE PLANT DISEASE -447 




Fig. 318. — Marasmius plicatus. After Fulton. 



448 THE FUNGI WHICH CAUSE PLANT DISEASE 

M. plicatus Wak. 

Pileus submembranous, convex or subcampanulate, glabrous, 
sulcate-striate, chestnut or light wine-colored; gills rather distant, 
white, basally attached; stipe slender, glabrous above, white 
downy below. 

Marasmius parasitism of sugar cane was first described by 
Wakker in 1895 ^"^ later by Howard. ^°- In these cases M. sacchari 
or varieties of it were identified. In 1908 Fulton described M. 
plicatus Wak. as the cause of serious sugar cane troubles in Louis- 
iana.^*^^ This fungus which exists first as a saprophyte resides 
primarily in the soil from which it grows over the stools and 
eventually penetrates living tissue, destroys many roots and 
smothers the developing buds. The white mycelium is found 
cementing the lower leaf sheaths to the cane. It is probable that 
several species are concerned. 

M. sacchari Wak. occurs on sugar cane in the oriental tropics. 

M. hawiiensis Cobb, is reported as associated with the preceding 
species in Hawaii. M. semiustus B. & C affects the stems, pedun- 
cles and inflorescence of the banana. M. equicrinis Miill. Banc. 
causes horse-hair blight of cacao and M. sarmentosus Fr. a simi- 
lar disease of the tea plant and of forest trees in India. 

Agariceae (p. 443) 

This tribe contains all the gill fungi and is characterized by a 
fleshy, putrescent sporophore; gills fleshy, rarely tough or leathery, 
weak, easily broken, not deliquescent, without milky juice. It is 
the largest tribe of the family. The genera are conveniently 
grouped as black, brown, rusty, pink or red, and white-spored 
forms. None of the black-spored species are knowTi as parasites. 

Amaurosporeae (brown-spored series) 

With a volva at base 1. Chitonia. 

Without a volva. 

Veil remaining on the stem as an annulus 

Gills free from the stem 2. Agaricus. 

Gills united with the stem 3. Stropharia. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



449 



Veil remaining attached to the margin of 
the pileus, often not apparent in very 

old specimens 4. Hypholoma, p. 450. 

Veil inconspicuous or wanting 

Gills free 5. Pilosace. 

Gills decurrent 6. Deconica. 

Gills adnate or sinuate 

Margin of pileus incurved when 

young 7. Psilocybe, p. 451. 

Margin of pileus always straight. ... 8. Psathyra. 

Phaeosporeae (Rusty-spored scries) 

Annulus continuous 

Veil single, forming the annulus 1. Pholiota, p. 452. 

Veil double, forming the annulus and 

deciduous scales on the pileus 2. Rozites. 

Annulus arachnoid, filamentous or evanes- 
cent, often not apparent in old speci- 
mens 

Gills adnate; terrestrial 3. Cortinarius. 

Gills decurrent; epiphytal 4. Flammula, p. 452. 

Annulus wanting 

Gills decurrent; stipe with a cartilaginous 

rind 5. Tubaria. 

Gills not decurrent 
Stipe fleshy 

Without a volva 

Pileus fibrinous or silky - 6. Inocybe. 

Pileus smooth and viscid ■ 7. Hebeloma. 

With a volva , 8. Locellina. 

Stipe with a cartilaginous rind 

Margin of pileus incurved when ^ 

young I 9. Naucoria. 

Margin of pileus straight 

Pileus viscid; gills free \ 10. PluteoIuSo 

Pileus not \nscid; gills attached. .. '11. Galera. 

Rhodosporeae (Pink-spored series) 

Stipe lateral 12. Claudopus. 

Stipe central. i 

Volva present; annulus wanting 13. Volvaria, p. 452. 



450 THE FUNGI WHICH CAUSE PLANT DISEASE 

Volva absent; annulus present 14. Annularia. 

Volva and annulus both wanting 

Gills free from the stipe 15. Pluteus, p. 45 1 . 

Gills adnate or sinuate 

Stipe fleshy 16. Entoloma. 

Stipe with a cartilaginous rind 

Pileus torn into scales 17. Leptonia. 

Pileus papillose, subcam})anulate . 18. Nolanea. 
Gills decurrent on the stipe 

Stipe fleshy 19. Clitopilus. 

Stipe with a cartilaginous rind 20. Eccilia. 

Leucosporeae (White-spored series) 

Stipe lateral, or none 21. Pleurotus, p. 454. 

Stipe central 

Volva and annulus both present 22. Amanita. 

Volva present; annulus none 23. Amantiopsis. 

Volva absent; annulus present 

Gills free from the stipe 24. Lepotia. 

Gills united to the stipe 

Pileus usually smooth 25. Armillaria, p. 455. 

Pileus floccose 26. Costinellus. 

Volva and annulus Ijoth absent 
Gills decurrent on the stipe 

Stipe fleshy 27. Clitocybe, p. 457. 

Stipe with a cartilaginous rind 28. Omphalia. 

Gills adnate, stipe with a cartilaginous 

rind 29. Collybia, p. 458. 

Gills sinuate 

Stipe fleshy 30. Tricholoma, p. 460. 

Stipe with a cartilaginous rind 

Pileus membranous, more or less 

striate 31. Mycena, p. 460. 

Pileus very thin, without a pelli- 
cle 32. Hiatula. 

Hypholoma Fries (p. 449) 

Fleshy; gills attached; annulus imperfect, or none; veil breaking 
up into fragments which are more or less persistent on the margin 
of the cap. 

About seventy species. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



451 



H. appendiculatum (Bui.) Karst. is perhaps parasitic, occurring 
at the bases of hving trees. 

H. fasciculare (Huds.) Fr. is said to grow parasitically upon 




Fui. 319. — Hypoloma appendiculatum. After Clements. 

roots, causing a white rot. It is mentioned as a parasite on rasp- 
berry roots in Australia. '°^ 

H. lateritium (Scha.) Schr. is also possibly parasitic on trees. 



Psilocybe Fries (p. 449) 

Pileus smooth, margin at first incurved; gills and spores at 
length brownish or purplish; stipe cartilaginous, hollow or stuffed, 
veil absent or rudimentary. 

About forty species. Fig. 320. 

P. spadicea (Scha.) Fr. is a weak wound parasite on various 
woody plants. 

P. henningsii Jung, is said to be occasionally injurious to 
winter grains ^°^ in Europe. 



452 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Pholiota Fries (p. 449) 

Pileus symmetrical, more or less thick, fleshy, with a veil 
which forms an annulus; gills adnate, becoming rusty at maturity. 
Fig. 321. 



P. 



aurivilla (Bat.) Quel, and P. 
deciduous 




Fig. 320. — Psilocybe pennata. 
After Cooke. 



squarrosa Miill. occur on 
trees, especially on the 
apple. 

P. spectabilis Fr. is occasionally 
parasitic on oaks. 

P. mutabilis (Scha.) Quel, is a root 
parasite on trees. 
P. adiposa Fries. 

Cap medium, 5-10 cm. wide, yellow, 
very sticky when moist, with spread- 
ing or erect rust-brown scales which 
sometimes disappear when old, convex 
to plane; stem 5-15 cm. by 1-2 cm., 
yellow, paler above and darker, scaly below the more or less im- 
perfect tufted ring, solid or stuffed; gills adnate, yellowish to rust- 
colored, broad, crowded; spores rust-colored, elliptic, 7-8 x 5 fx. 
The name may refer to the sticky cap. 

Chiefly a saprophyte, occasionally on living trees, both decid- 
uous trees and conifers, as a wound parasite. 

P. destruens Brand, occurs on poplar; P. cervinus Scha. on 
various trees. 

Flammula Fries (p. 449) 

Pileus fleshy, margin at first incurved; stipe fleshy, fibrous, 
well marked by the bright yellow or orange colored cap. 

About sixty species. 

F. alnicola Fr. is probably a root parasite. ^°° 

F. penetrans Fr. and F. spumosa Fr. are regarded by Cavara ^°^ 
as root parasites of forest trees. 



Volvaria Fries (p. 449) 
Flesh J''; gills free, white, later pink; spores ellipsoid, smooth; 



THE FUNGI WHICH CAUSE PLANT DISEASE 



453 



annulus none; volva present. Easily distinguished from all other 
pink-spored genera by the volva. Fig. 322, 
About thirty-six species. 




Fig. 321. — Pholiota adiposa.^ After Clements. 

V. bombycina (Scha.) Quel. 

Cap large, 8-25 cm. wide, all white and silky, more rarely some- 
what scaly, hemispheric or bell-shaped to convex; stem 8-12 cm. 
by 1-2 cm., white, smooth, tapering upward, solid, volva large 
and spreading; gills free, salmon-pink, crowded, spores elliptic, 
6-7 X 4 /i. It is often parasitic on various trees. 



454 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Piute US Fries (p. 450) 

Pileus fleshy, regular; separating easily from the stipe; gills 
free; volva and annulus both absent; spores elliptic. 

P. cervinus Scha. Fig. 323. 

Cap large, 5-16 cm. wide, usually 
.'■ome shade of brown, from grayish or 
yellowish to blackish-brown, more or 
less fibrous or hairy on the disk, some- 
times sticky, convex or plane; stem 7- 
15 cm. by 3^-1 cm., brownish, smooth 
or black-hairy, solid; gills free, pink, 
broad; spores pink, rarely greenish, 
globoid, 7-8 X 5-6 n. 

A common saprophyte which is oc- 
casionally parasitic. 

Pleurotus Fries (p. 450) 

Pileus laterally sessile, or excentrically 
stipitate. Fig. 324. 

A genus of about two hundred fifty 
species. 

P. ostreatus Jacq. 

Cap large, 7-24 cm. wide, white, gray 
or tan, smooth or more or less scaly in 
age, convex or plane, shelf or shell- 
shaped, more or less lobed and torn at 
the margin; stem short and lateral, or none, white, solid, more or 
less hairy at base; gills long-decurrent, connected by veins on the 
stem, white or yellowish ; spores elliptic, 8-10 x 4-5 /x. 
Common on deciduous trees, mainly saprophytic. 
P. salignus Schrad. is often parasitic on willow, poplar, mul- 
berry, etc. 
P. ulmarius Bui. 

Cap large, 8-15 cm. wide, white, whitish or tan, often brownish 
toward the center, smooth, often cracked, usually convex, some- 
times plane; stem long and stout, often nearly central, 5-12 cm. 
by 2-3 cm., white or tan, smooth or hairy toward the base, solid. 



^^^^^H^^'^ 


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^B 


Va 


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^^H 


wKm M^ 


w 


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^^Kj^jlj^^HM 


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ViG.. 322. — Volvaria bomhy 
cina. After Clements. 



THE FUNGI WHICH CAUSE PLANT DISEASE 455 

elastic, often curved; gills annexed or sinuate, whitish, broad, 
close; spores globose, 5-6 fi. 

Parasitic on elm and maple or usually a saprophyte. 




Fig. 323. — Piute us cciviuus. Alter Ciemeuta. 



P. nidulans Pers. occurs on roots of trees in Europe. 
Other questionable parasites are: P. atrocoeruleus Fr. on wil- 
low; P. mitis Pers. on pine; P. corticatus Fir. on "poplar. 

Armillaria Fries (p. 450) 

Fleshy, the substance of the pileus and stipe continuous; annulus 
fixed; gills usually attached, white; spores clavate, ellipsoid or 
ovate, smooth. 

About sixty species. Figs. 325, 326. 

An extensive list of members of the genus, under the name 
Agaricus, found growing upon woody plants has been compiled by 
Wilcox. 1°^ 

A. mellea (Vahl.) Quel."' '"' "' '"' 

Cap large, 3-15 cm. wide, usually honey-colored, but varying 
through all shades of yellow to bro\vn, typically marked with 
small tufts of brownish or blackish hairs, especially toward the 
center, though sometimes woolly or entirely smooth, margin often 
striate, convex to expanded; stem tall, stout, 3-15 cm. by 6-20 mm., 
whitish, yellowish, or brownish, especially below the ring, smooth 
or scaly, hollow or stuffed, ring usually thicldsh and conspicuous, 



456 



THE FUNGI WHICH CAUSE PLANT DISEASE 



but sometimes thin or even lacking; gills touching broadly or 
running down the stem, Avhitish or yellowish; spores elliptic or 
rounded, 7-10 m- 

This is a common wound parasite of conifers and deciduous 
trees, causing a root-rot. It also causes a potato disease in Aus- 
tralia.^"^ The abundant mycelium is white and extends a meter 



Hi 


HF^^ 




^H 


■H 


J^m 


ggj^gjj^^y't g^jferaaayg^^gBB 




1^^ 


^^1 


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^^^ 


^^H 


''■>'^w^|^| 


H|^ 




m 


H^ 


R»S^ 


^^^^^^^n^^ 




BS^^I 


^^^^^^Q 


^m 


mBM 


■ffi^^^^^^^^^^H 


H 


^H 


^^ 


I^^HsH 




|hH 


^^^^^1^^^^ 


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^1 


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Fig. 324. — Pleurotus ostreatus. After Clements. 



or more through the wood and bark, aggregating under or on the 
bark to form shining hard gray-black intertangled cords (rhizo- 
morphs) 1-2 mm. in diameter often reaching out to great distances 
through the earth. Fig, 326. Sheets of white felt also occur. 

The young mycelium grows into the cambium layer, attacking 
living cells and often encircling the tree. In the living cortex it 
presents a characteristic fasciated skin-like appearance. 



THE FUNCil WHICH CAUSE PLANT DISEASE 457 

The sporophores are borne in clusters in autumn on the ground 
or on the Ixark. 

The spores, sowa in phim decoction, develop a mycelium which 
soon produces rhizomorphs. These advancing give off delicate 
hypha; which may penetrate into the host. The mycelium spreads 





p^BB 


HMM 






''■'^#*i|3 




^ - ' s^iC|R|^^pfl^|^^^^HH|^^| 


j% 




hhh 


jKV 


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I^^^H 


5 ^ 


'''V*'\l\\iMll!IL'i!li!ilJjiMMl^^iS 


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^^^I^^^^^B^^^. ■ «<r_jfl^^^H 


^ '"^^!^H^^' '-^^B 



Fig. 325. — Armillaria mellea. After Clements. 

most rapidly through the medullary rays and from them into other 
tissue elements. 

A. fuscipes Fetch causes a root disease of Acacia in Ceylon. 

A. mucida (Schrad.) Quel, is reported as a wound parasite of the 
beech. 

Clitocybe Fries (p. 450) 

Pileus more or less fleshy, margin at first incurved; stipe fleshy, 
often becoming hollow; gills decurrent. 
About ninety species. Fig. 427. 



458 



THE FUNGI WHICH CAUSE PLANT DISEASE 



C. parasitica Wil.^o^ 

Growing in dense clusters; pileus 6-8 cm., convex or umbonate, 

usually minutely scaly, mottled 
l)uff to yellow-brown in color; 
gills paler, becoming mottled, 
at first noticeably decurrent; 
stipe 10-16 cm. high, up to 
1 cm. thick, solid, usually 
curved, darker than the pileus; 
black rhizomorphs present. 

It differs from Armillaria 
mellea in having no annulus, 
and in growing in denser clus- 
ters. 

The fungus causes a root- 
rot very similar to that caused 
by Armillaria mellea. There 
are present typical subcortical 
strands, mostly between the 
cortex and cambium and some- 
times characteristic subterranean black rhizomorphs adhering 
close to the cortex of the roots. 

Fungous branches enter the wood chiefly through the medullary 
rays and there is later rapid vertical growth through the vessels 
and tracheids. The cell contents are destroyed, the hyphse often 
forming loops around the nucleus. The sporophores occur in 
groups at the base of the tree after the disease is well developed. 
An extensive bibliography is given by Wilcox. ^°'^ 



^H^" /'-"^-vc" ' 




\ 


n ris^ibjli^'^'' x'Swfi 


m 


" % 


„ 1 '.^ZT^wf^^f9lir^w-/it^Jt 


f 


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"^ 




^^^^^^^ /Jw" 






i v^>C--*<y^ M ^ VwlW; /^^ 






i.j*|r 







Fiu. 326. — Rhizomorphs of A. mellea. 
After Freeman. 



Collybia Fries (p. 450) 

Pileus thin, fleshy, margin at first incurved; stipe cartilaginous. 

About two hundred seventy-five species. Fig. 329. 

C. velutipes Curt. 

Cap 2-8 cm. wide, yellow-brown or reddish brown, rarely paler 
except toward the margin, smooth, very sticky when moist, con- 
vex to plane or somewhat recurved, often excentric or irregular 
through pressure. 



THE FUNGI WHICH CAI^SE PLANT DISEASE 459 




Fig. 327. — Clitocybe parasitica. After Wilcox 




iG. 328.— Clitocybe parasitica, mycelium entering medullary ray. After Wilcox. 



460 



THE FUNGI WHICH CAUSE PLANT DISEASE 




Fig. 329.— Collybia velutipes. 
Lloyd. 



After 



A common saprophyte which is reported by Stewart ^°^ as the 
probable cause of death of the horse-chestnut. It has also 

been reported in Europe as a 
parasite. 

Tricholoma Fries (p. 450) 

Stout and fleshy, stipe 
;md pileus of the same sub- 
stance; gills sinuate or ad- 
nate. Fig. 330. 

T. rutilans Scha. occurs on 
pine roots; T. saponaceum Fr. 
on various tree roots. 

Mycena Fries (p. 450) 

Small; pileus usually bell- 
shaped, rarely umbilicate, membranous and more or less striate, 
at first with the straight margin applied to the stipe; gills only 
slightly toothed, not decurrent or only so by a tooth; stipe slen- 
der, cartilaginous, usually 
hollow. Fig. 331. 

A genus of some three 
hundred species. 

M. epipterygia Scop. 

Five to ten cm. high; 
pileus 1-2 cm. broad, vis- 
cid when moist, ovate to 
conic or campanulate, 
later more expanded, ob- 
tuse, the margin striate, 
sometimes minutely 
toothed, grayish, in age 
often reddish; stipe 2 mm. 
thick, flexuous or straight 
with soft hairs at the base; gills decurrent by a small tooth, 
varying in color from whitish through gray to a tinge of blue or red. 

Usually a saprophyte, but injurious to various kinds of trees. 
Widely distributed in the North temperate zone. 




Fig. 330.— Tricholoma. After Lloyd. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



461 




462 THE FUNGI WHICH CAUSE PLANT DISEASE 



PhaUales (p. 395) 

Mycelium rhizomorphic ; sporophore with a fertile portion, the 
gleba, which contains a series of labyrinthine spore chambers, 
these lined by a hymenium of closely approximated basidia, the 
supporting tissue parenchymatous, spongy and elastic in texture, 
forming a receptacle which varies in size and form in the different 
genera. Except in Rhizogaster the young sporophore is volvate, 
and at the bursting of the volva immediately assumes its mature 
size and form. 

An order of less than fifty species of interesting, yet from their 
foul odor most disagreeable fungi. At present they are regarded 
as mainly saprophytes. 

Key to Families of PhaUales 

Receptacle stipitate, tubular or cylin- 
dric, capitate, with the gleba ex- 
ternal 1. Phallaceae, p. 462. 

Receptacle latticed or irregularly 
branched, sessile or stalked; gleba en- 
closed by the receptacle 2. Clathraceae, p. 463. 

Phallaceae 

Key to Genera of Phallaceae 

Gleba borne directly on the upper portion of 
the stem; no special pileus 

Gleba smooth, even 1 . Mutinus. 

Gleba papillate or uneven 2. Jansia. 

Gleba covered by a rudimentary network 3. Floccomutinus. 
Gleba borne on the outer surface of a special 
pileus 
Pileus even, rugose, or reticulate 

Veil poorly developed or none 4. Phallus, p. 463. 

Veil well developed 

Surface of the pileus regularly reticu- 
late 5. Dictyophora, p. 463. 

Surface of the pileus irregularly folded 

and convoluted 6. Clautriavia. 

Pileus lamellate 7. Itajahya. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



463 




Phallus Linnaeus (p. 462) 

Stipe cylindric, even, bearing at the apex a 
smooth, rugose, or reticulate pileus. 

Less than ten species are known. The follow- 
ing are of economic importance. 

P. impudicus L. 

This is one of the most widely distributed 
species of the genus, but not so common in 
America as in Europe. It is reported ^'^ as the 
cause of a root disease of the grape in Hungary. 

P. rubicundus Bosc. 

Cobb ^^^ has described a disease of sugar cane 
as due to Ithyphallus coralloides. Lloyd, ^'- 
however, refers the causal fungus to the present F i g. 332. —Phallus 

1 . , ji i 11 ii 1 impudicus. After 

species, since he considers that all the red Lloyd, 
forms of "Phallus" constitute a single species. 

Dictyophora Desvaux (p. 462) 

A species of this genus is suspected by Cobb ^^^ as one of the 
causal fungi in a root disease of sugar cane in Hawaii. 

Clathraceae (p. 462) 

The receptacle consists of a series of arms which are either 
spreading, erect, or latticed. 

Key to Genera of Clathraceae 
Receptacle of free arms, or lobes at the sum- 
mit of the stipe 

Stipe columnar, arms free L Lysurus. 

Stipe enlarged upwards 

Limb of the receptacle with suberect 

lobes 2. Anthurus. 

Limb of the receptacle with radiating 

lobes 3. AsercB. 

Receptacle of simple, erect, columns, apical- 
ly united and fertile only on their inner 
side 

Sessile 4. Laternea, p. 464. 

Stalked 5. Pseudocolus. 



464 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Receptacle clathral^e or latticed 

Sessile 6. Clathrus. 

Stalked 

Receptacle a simple net 

Stipe simple 7. 

Borne on a series of columns which 
are united basally into a hollow 

tube 

Receptacle with the network covered 

with knot-like projections 9. Klachbrennera. 



7. Simblum. 



Colus. 



Lateraea Turpin (p. 463) 

Receptacle sessile, of upright, convergent 
columns, apically united and fertile only on 
the inner surface. 

L. columnata (Bosc.) Ness, is recorded by 
Cobb ^^"^ as one of the fungi of the root disease 
of sugar cane in Hawaii. The species is rather 
cammon in the Southern United States, South 
America, the West Indies and Hawaii. 

Lycoperdales (p. 395) 

Mycelium arachnoid to rhizomorphic; sporo- 
phores from the first appearing as small balls 
which enlarge to maturity, gleba internal at 
maturity, becoming a powdery spore-mass; base 
of the sporophore sterile ; peridium double or single, parenchyma- 
tous, separating into flakes or breaking regularlj''; fertile hyphse, 
persistent in the spore mass as a capillitium which is usually at- 
tached to the columella. 

A single family Lycoperdaceae with species which are usually 
saprophytes. 




Fig. 333.— Latcr- 
nea columnata. 
After Lloyd. 



Key to Genera of Lycoperdaceae 

Outer peridium fragile, more or less decidu- 
ous, often warty, spiny or scaly 
Capillitium of an even thickness, not 
branched 



THE FUNGI WHICH CAUSE PLANT DISEASE 



465 



Sporophore with a pronounced sterile 

persistent base 1. Lycoperdon, p. 465. 

Sporophore without a pronounced 
sterile base 
Inner peridium opening irregularly. . 2. Globaria. 
Inner peridium opening by a basal 
pore, the outer peridium break- 
ing equatorially and the upper 
half with the attached inner 

peridium forcefully ejected 3. Catastoma. 

Capillitium free, short-branched with 
pointed ends 
Sporophore with a pronounced per- 
sistent sterile base 4. Bovistella. 

Sporophore without a pronounced 
sterile base 
Inner peridium papery, opening by an 

apical mouth 5. Bovista. 

Inner peridium thick, breaking 

irregularly, capilhtium spiny. . . 6. Mycenastrum. 
Outer peridium splitting into star-like re- 
flexed, persistent segments 
Inner peridium opening by a single mouth 7. Geaster. 
Inner peridium opening by several mouths 8. Myriostoma. 

Lycoperdon Tournefort 

Sessile, with a pronounced 
sterile base; peridium thin, 
opening regularly by an apical ^^^i- ^y^^^_ 

perforation, smooth, warty or ^^^^^ " ^ 
spiny; spore-mass and capilli- ^^K- I "^\ 

tium filling the interior of the ^^ ™^ ^ 

sporophore with echinulate 
spores and even, simple hy- ^m ..^-i 

phiP. 

L. gemmatum Bat. is re- 
ported by Cavara ^^^ on fir 

trees in Italy, sending its ^^^ 334.— Lycoperdon gemmatum. After 

rhizomorphic mycelial strands Lloyd. 

through cambium and bark causing the destruction of both. 




BIBLIOGRAPHY OF BASIDIOMYCETES 

1 Lutman, B. F., Sc. 31: 747, 1910. 

* Dangeard, P., Ser. L. Bot. 3: 240, 1892. 
3 Harper, R. A., Am. Nat. 44: 544. 

* Harper, R. A., Trans. Wis. Acad. Sci. 12: 483, 1899. 

' Clinton, G. P., Proc. Boston, Soc. Nat. Hist. 31: 1904. 

" Wolff, R., Der Brand d. Getreides, Halle, 1874. 

' Brefeld, 0., Unt. Heft £, also Heft, 11: 1895. 

' Jensen, J. L., Les. Charbon des C^r^ales, July 4, 1889. 

» Prevost, B., Memoir, Paris 29: 1807. 

1° Lobelius, I cones stirpium, 36. 

" Persoon, Synopsis method fung: 224. 

" Jensen, J. L., Om Koen, Brand, 56, 1885. 

" Maddox, F., D. of Ag. Tasmania, 1895, and 1897. 

" Wakagawa, S., Bull. Imp. Cent. Ag. St. Japan 1: 1907. 

15 Brefeld, 0., Klub. d. Landw. z. Berlin, 466, 1903. 

i» Hecke, Zeit. f . Land. Vers, in Oestr. 1904. 

" Hecke, Ber. d. deut. Bot. Ges. 23: 250. 

'8 Freeman, E. M. and Johnson, E. C, B. P. I. 152: 1909. 

1' Arthur, J. C, Stuart, W., Ind. R. 12: 84, 1900. 

2" Kuhn, Hedwigia, 2: 5, 1858. 

» Brefeld, O., Unt. Aus d. Gesamat d. Myk. Heft. 11: 1895. 

"Hori, S., Bull. Imp. Cent. Sta. Japan 1: 73, 1905. 

2» Clinton, G. P., 111. Bui. 47: 1897. 

2" Clinton, G. P., 111. Bui. 57: 1900. 

" Bubak, F., Zeit. Land Vers. Ost. 12: 545. 

"Anderson, P. A., S. C. B. 41: 1899. 

'-' Farlow, W. G., Mass. St. Bd. Agr. R. 24: 164, 1877. 

^^Thaxter, R., Coim. R. 1899: 129, 1890. 

29 Neger, F. W., Tharand, Fors. Jahr. 60: 222. 

'" Bubak, Zeit. Land. Vers. St. Oest. 477, 1901. 

3' Halsted, B. D., Bull. Torn Bot. Club 17: 95, 1890. 

32 Lagerheim, G. von, J. Myc. 7: 49, 1891. 

•" Nichols, S. P., Trans. Wis. Acad. Sc. 15: 1905. 

*See footnote, p. 53. 
466 



BIBLIOGRAPHY OF BASIDIOMVCETES 467 

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" Wager, H., Ann. Bot. 8: 322, 1894. 

38 Dangeard, P., Le. Bot. 1895. 

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^o Shear, C. L., B. P. I. 110: 36, 1907. 

*' McRae, W., Agr. Reas. Inst. Pusa. B. IS: July, 1910. 

*^ Viali and Boyer, C. R. 1891: 1148. 

^^ Seward, A. C., Fossil Plants for Students Botany and Geology 1: 1898. 

'' Noack, Bol. Inst. Agron. Sco. Paulo 9: 1, 1898. 

*' Stevens, F. L., and Hall, J. G., Sc. 26: 724, 1907. 

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'^ Frank, B., Ber. D. deut. Bot. Gez. 1: 62, 1883. 

*« Ilcdw. IS: 127, 1SS3. 

« PriUieux and Delacroix, B. S. M. d. Fr. 5.- 221, 1891. 

'0 Bernard, C., Dept. Agr. Indes Neerland 6: 55, 1907. 

51 Eustace, H. J., N. Y. (Geneva) B. 235: 1903. 

" Viala and Boyer, C. R. 112: 1148, 1891. 

" Peglion, Bull, di Entom. Agr. e. Pat. Veget. 4: 302, 1897. 

" Giissow, H. T., Zeit. 16: 135, 1906. 

"5 Duggar, B. M., N. Y. (Cornell) B. 186: 266, 1901. 

" Rolfs, F. M., Col. B. 91: 1904. 

" Edgerton, C. W., Phytop. 1: 16, 1911, also La. B. 126. 

68 Zimmerman, A., C. Bak. 7; 102, 1901. 

69 Hennings, P., C. Bak. 9: 939, 1902. 

«o Fetch, Jour. Roy. Bot. Card. Ceylon 4: July, 1909. 
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62 Potter, Rept. Trans. English Arboricult. Soc. 105: 1901-1902. 

63 Gussow, H. T., Rept. Expt. Farms Ottawa 110: 269. 
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66 Galloway, B. T., J. Myc. 6: 113, 1891. 

66 Atkinson, G. F., La. Geol. Sur. 335, 1889. 

6' Schrenk, H. von, and Spaulding, P., B. P. I. 149: 1909 

68 Thiimen, v., Zeit. 1: 132, 1891. 

69 Shiljakow, Scripta Bot. Hort. Petrop 3: 84, 1890. 

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" Banker, H. J., Bull. Torrey. Bot. Club, 36: 341, 1909. 

" Ballou, H. W., Sci. Amer. 99: 454, 1908. 



468 THE FUNGI WHICH CAUSE PLANT DISEASE 

74 Schrenk, H. von, B. V. P. P. 25: 1900. 

" Petch. T., Trop. Agr. & May. Ceylon Agric. Soc. 28: 292, 1907. 
76 Fetch, T., Cir. & Agr. Jour. Roy. Bot. Gard. Ceylon 3: 277, 
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80 Galloway, B. T. and Woods, A. R, Y. B. 237: 1896. 

81 BuUer, A. H. R., Jour. Ec. Biol. 1906. 

8= Hedgcock, G. G., Mycologia 2: 155, 1910. 

«3 Mayr. H., Bot. Cent. 19: 22, 1884. 

84 Schrenk, H. von, Bur. Forestry, B. 57: 49, 1902. 

86 Kew Misc. Bui. 1910: 95, 1896. 

86 Pollock, J. B., Sc. 31: 754, 1910. 

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83 Spaulding, P., Sc. 26: 479, 1907. 

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100 Hennings, P., Zeit. 13: 198, 1903. 

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112 Lloyd, C. C, Synopsis of the Known Phalloids 10: 1909. 



BIBLIOGRAPHY OF BASIDIOMYCETES 469 

"3 Cobb, N. A., Hawaiian Sugar Planters' Expt. Sta., Div. Path, and 
Physiol. Bui 6: 1909. 

"* Cavara, F., Stazioni seperim. agrar. ital. 29: 788, 1896. 

11'' Dangeard, P. A., Le Bot. 4: 12, 1894. 

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1'^ Sclby, A. D., Ohio B. 6^: 115, 1895. 

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1" Selby, A. D., Ohio B. 122: 71, 1900. 

i« Setchell, W. A., Proc. Amer. Acad. Arts. Sci. 26: 13, 1891. 

i« Setchell, W. A., Ann. Bot. 6: 1, 1892. 

i« Takahashi, Y., Tok. Bot. Mag. 10: 16, 1896. 

15° Wakker, J. H., Bring. Jahr. Wiss. Bot. 2/-^: 532, 1892. 

1" Wolff, R., Bot. Zeit. 31: 657, 673, 689, 1873. 

152 Magnus, P., Ber. deut. Bot. Ges. 1^: 216, 1896. 



470 THE FUNGI WHICH CAUSE PLANT DISEASE 

" Griffiths, D., B. P. I. 38: 43, 1903. 

" Setchell, W. A., Bot. Gaz. 19: 185, 1894. 

" Halsted, B. D., N. J. B. 170. 

^« Cornu, M. B., Soc. Bot. Fr. 30: 130, 1883. 

67 Cunningham, D. D., Sci. Mem. Med. Off. Army India, 3: 27, 1887. 

58 Edgerton, La. B. 126, 1911. 

55 Rech. Basidiomycetes Lons-le-Saumier, 1902. 

«° Duggar, B. M., and Stewart, F. C., N. Y. (Cornell) B. 186: 1901. 

«i Rolfs, F. M., Col. B. 70: 1902. 

«2 Rolfs, F. M., Fla. R. 1905. 

«' Rolfs, F. M., Col. B. 91: 1904. 

«4 Bourdot and Golzin, B. S. M. d. Fr. 37: 223, 1911. 

"5 Edgerton, C. W., La. B. 126: 1911. 

«6 Bary, A. De., Mon. Ber. Akad. Wiss. Berhn, 1865. 

6' Blackman, V. H., New Phytologist, 2: 10, 1903. 

' Bolley, H. L., Agr. Sci. 5: 263, 1891. Bolley and Pritchard, F. J., 
Bot. Gaz. 5^; 169, 1911. 

Bolley, H. L., N. D. Agr. Expt. Sta. Bull. 68, 1906. 
70 Brefeld, Oscar, Untersuchungen, 14: 154, 1908. 

' Carleton, M. A., Div. V. P. P. B., 16, 1899. 

2 Carleton, M. A., B. P. L B. 63, 1904. 

' Christman, A. H., Trans. Wis. Acad. Sc. 15: 98, 1904. 

* Eriksson, J. and Henning, Ernst., Die Getreideroste, Stokholm, 1896. 

5 Magnus, P., Ber. deuts. Bot. Ges., 9: 90, 1891. 

8 Schceler, N. P., Landcekomminske Tidender 8: 289, 1818. 

■' Smith, W. G., Card. Chron. 2: 21," 1884. 

8 Arthur, J. C, Bot. Gaz. 29: 268, 1900. 

5 Blackman, V. H., Ann. Bot. 18: 323, 1904. 

80 Christman, A. H., Bot. Gaz. U: 81, 1907. 

81 Olive, E. W., Ann. Bot. 22: 331, 1908. 

8* Richards, H. M., Proc. Amer. Acad. Arts and Sci. 31: 255, 1895. 
83 Arthur, J. C, J. Myc. 12: 11, 1906. 
8^ Arthur, J. C, J. Myc. 8: 51, 1902. 
85 Arthur, J. C, Bot. Gaz. 35: 10, 1903. 
8« Arthur, J. C, J. Myc. 11: 8, 1905. 
8' Arthur, J. C, Torr. Bull. 32: 35, 1905. 
88 Carleton, M. A., Sc. 13: 249, 1900. 
89Kurssanow, Zeit. f. Bot. 2: 81, 1910. 
'0 Eriksson, J., Biol. Cent. 30: 618, 1910. 
91 Zach, Sitz. d. Kais Ak. d. Wiss. Wien., Math.— Nat. Kl. 119, Ab. 

/.•307, 1910. 



BIBLIOGRAPHY OF liASIDIOMYCETES 471 

1" Ward, H. M., Phil. Trans. Bot. 196: 29, 1003. 

'" Arthur, J. C, Results Cong. Int. d. Bot. Vienne, 331, 1905. 

»«* P. Rico. R. 449, 1903. 

'« Arthur, J. C, and Kern, F. D., Torr. Bull. 33: 403, 1906. 

»»« Clinton, G. P., Sc. 25: 289, 1907. 

1" Clinton, G. P., Ct. R. 369, 1907. 

•^« Chittenden, F. L., Jour. Roy. Hort. Soc. London, 33: 511, 1908. 

19^ Galloway, B. T., Bot. Gaz. 22: 443, 1896. 

^oo Kellerman, W. A., J. Myc. 11: 32, 1905. 

'"i Fraser, W. P., Sc. 30: 814, 1909. 

202 Selby, A. D., 0. B. 21^: 1910. 

^o' Bolley, L. H., N. D. B. 55: 189, 1903. 

20^ Fischer, E., Zeit. 12: 193, 1902. 

205 Plowright, Zeit. 1: 131, 1891. 

206 Farlow, W. G., Proc. Am. Ac. A. & S. 20: 311, 1885. 
20' Farlow, W. G., Bot. Gaz. 11: 234, 1886. 

208 Pammel, L. H., la. B. 8^: 1905. 

209 Richards, H. M., Bot. Gaz. U: 211, 1889. 

210 Thaxter, R., Bot. Gaz. 1^: 163, 1889. 

211 Stewart, F. C, N. Y. (Geneva) B. 328: 1911. 
2i2Biedenkopf, H., Zeit. 4: 321, 1894. 

213 Halsted, B. D., D. Agr. R. 288. 
21* Heald, F. D., Neb. R. 22: 1909. 

215 Underwood, L. M. and Earle, F. S., Bot. Gaz. 22: 225, 1896. 

216 Pammel, L. H., J. Myc. 7: 102, 1892. 
21' Thaxter, R., Conn. B. 107: 1891. 

218 Shirae, M., Zeit. 10: 1, 1900. 

219 Whetzel, H. H., N. Y. (Cornell) B. 239: 298, 1906. 

220 Kirk, I. W., New Zeal. D. Agr. R. 13: 405, 1905. 

221 Howell, J. K., N. Y. (Cornell), B. 2J^: 129, 1890. 

222 Pammell, L. H., la. B. 13: 51, 1891. 

223 Kern, F. D., Phyto. ^; 3, 1911. 

224 Lagerheira, G., Svensk. Bot. Tid. 3: 18, 1909. 

225 Cobb, N. A., N. S. Wales, Sydney, 1893. 

226 Arthur, J. C, Bot. Gaz. 16: 321, 1891. 
22' Stewart, F. C, Geneva R. 15: 461, 1895. 

228 Stewart, F. C, Geneva B. 100: 1896. 

229 Stuart, Wm., Vt. R. 8: 115, 1894. 

230 Stevens, F. L., Bot. Gaz. 26: 377, 1898. 

231 Delacroix, Bull. Soc. M. d. Fr. 18: 14, 1902. 

232 Scribner, F. L., D. Agr. R. 353, 1887. 



472 THE FUNGI WHICH CAUSE PLANT DISEASE 

2" Transchel, Trav. Mus. Bot. Acad. Sc. St. Pet. 2: 67, 1905. 
^^^ Klebahn, H., Zeit. 5: 76, 1895. 
"^ Halsted, B. D., N. J. B. 129: 1898. 
"8 Arthur, J. C, Ind. R. 13: 1901. 
2»^ Smith, R. E., Bot. Gaz. 38: 19, 1904. 
"8 Smith, R. E., Cal. Bui. 172: 1906. 
"' Smith, R. E., Cal. Bui. 165: 1905. 
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2<i Stevens, F. L., Pop. Sc. Mo. May, 1911. 
2" E. S. R. 16: 380. 
2« Bates, J. M., J. Myc. 9: 219. 
2" Bates, J. M., Sc. 16: 138, 1902. 
2« Trabut, L., Bui. Agr. Alg. & Tun. 13: 355, 1907. 
"9 Olive, E. W., S. D. B. 109: 1908. 
=>« Ward, M. H., Ann. Bot. 2: 217, 1888. 
2« Eriksson & Henning, Zeit. 4: 1894. 
2« Pritchard, F. J., Bot. Gaz. 52: 169, 1911. 

"0 Butler, E. J. and Hayman, J. M., India D. Ag. R. 1906, Bot. Ser. 1. 
2^1 Lagerheim, G., Bot. Cent. 54. 324, 1893; Jour. Myc. 7: 327, 1891. 
2" Barclay, A., Jour. Bot. 30, 1892. 

2" Zukal, H., Untersuchungen iiber die Rostpilzkrankheiten des Get- 
reides in Oesterreich-Ungarn 10: 16, 1900. 

2" Loverdo, J., Les maladies cryptogamiques des cereales, Paris, 1892. 

«5 Lagerheim, G., Jour. Myc. 7;, 327, 1891. 

"6 Ward, H. M., Ann. Bot. 2: 229, 1888. 

2" Dorset, P. H., Am. Flor. 15: 246, 1899. 

"8 Jaczewski, Zeit. 20: 321, 1910. 

259 Eriksson, J., Ber. d. deut. Bot. Gez. 12: 292, 1894. 

280 Arthur, J. C, Bot. Gaz. 38: 64, 1904. 

2" Arthur, J. C, Sc. 29: 270, 1909. 

2''2 Halsted, B. D., Bull. Torr. Bot. CI. 25: 331, 1898. 

263 Dudley, W. R., N. Y. (Cornell) B. 25: 154, 189,0. 

26" Tabenhaus, J. J., Phytop. 1: 55, 1911. 

286 Eriksson, J., C. V,sk..31: 93, 1911. 

266 Arthur, J. C, Ind. B. 85: 143, 1900. 

267 Jacky, E., Zeit 10: 132, 1900. 

268 Stone, G. E., and Smith, R. E., Mass. R. 9: (Hatch) 1896: 176, 1898. 

269 Arthur, J. C. and Holway, E. W. D., Minn. Bot. St. B. 2: 631, 1901. 
2'o Chifflot, J., J. Soc. Nat. Hort. Fr. 4: 348, 1907. 

2" Kusano, S., Bull. Coll. Agr. Tokyo Imp. Univ. 8: 27, 1908. 
272 Clinton, G. P., 111. B. 29: 273, 1893. 



BIBLIOGRAPHY OF BASIDIOMYCETES 473 

"3 Newcomb, F. C, J. Myc. 6: 106, 1890. 

"■» Richards, H. M., Proc. Am. Acad. A. & So. 30: 30, 1893. 

2" Tranzschel, W., Hedw. 32: 257, 1893. 

"6 Arthur, J. C, Torreya, 9: 21, 1909. 

2" Kirk, T. W. and Cockayne, A. H., N. Zeal. D. Agr. R. 16: 108, 1908. 

"8 Cook, M. C, Jour. Roy. Hort. Soc. London, 26: 1901. 

2" Bartlett, A. W., R. Bot. Card. British Guiana, 20: 1906-1907. 

280 Montmartini, L., Atti. Inst. Bot. Univ. Pavia, 1904. 

281 Kusano, S., Bull. Co. Imp. Tokyo, 1908. 

282 Pettis, C. R., Forest Quart. 7: 231, 1909. 

283 Hennings, P., Zeit. 12: 129, 1902. 

284 Stewart, F. C, Geneva, T. B. 2: 62, 1906. 

285 Spaulding, P., B. P. I. Circ. 38: 1909. 

286 Spaulding, P., B. P. I. Bui. 206: 19II. 
28V Hedgcock, G., Sc. 31: 751, 1910. 

288 Shear, C. L., J. Myc. 12: 89, 1906. 

289 Farlow, W. G., Anniv. Mem. Boston Soc. Nat. Hist. 1880. 
29oldem, R. ii;343, 1898. 

291 Kuhn, J., Bot. Zeit. 27: 540, 1869. 

292 Freeman, Ann. Bot. 16: 487, 1902. 

29' Ward, H. M., Ann. Bot. 16: 233, 1902. 
294 McAlpine, D., Vict. D. Ag. 5: I, 1891. 
296 Kusano, S., Coll. Agr. Imp. Univ. Tokyo, 1908. 

296 Roze, B. S. M. Fr. 88: 1900. 

297 IClebalin, H., Ber. d. Deut. Bot. Gaz. 8. 59. 1890. 

298 Klebahn, H., Hedw. 29, 27, 1890. 

299 Tubeuf, K., C. Bak. 7, 445. 
3ooHaLsted, B. D., N. J. R. 391, 1893. 
'01 Halsted, B. D., N. J. R. 279, 1892. 

302 Lloyd, F. E. and Ridgway, C. S., Ala. B. D. Agr. 39: 1911. 

303 Johnson, E. C, B. P. I. 22J^: 1911. 

304 Trelease, Wm., Trans. Wis. Acad. 131, 1882. 
306 Kern, F. D , Torrya 9: 4, 1909. 

306 Freeman, E. M. and Johnson, E. C, B. P. I. 216: 1911. 

307 Eriksson, J. P., Ark. f. Bot. Stockholm 8: 1909. 

308 Arthur, J. C, Proc. Soc. Prom. Agr. Sc. 23: 1902. 

309 Arthur, J. C, J. Myc. 11: 53, 1905. 

310 Stewart, F. C, N. Y. (Geneva) B. 328: 1910. 
«ii Klebahn, Zeit. 2: 18, 1902. 

312 Eriksson, J., Kung. Svens, Vet.— Akad. Hand. B. 317: 6, 1904. 

313 Sappin-Trouffy, P., C. R. 116: 211 and 1304, 1894. 



474 THE FUNGI WHICH CAUSE PLANT DISEASE 

"* Dangeard, P. A., C. R. 116: 267, 1893. 
'1^ Pairault, G. and Raciborski, M., Jour. d. Bot. 9: 318, 1895. 
"6 Istvanffi, G., Ber. d. Deut. Bot. Gez. 1895. 
317 Juel, Pring. Jahr. 1898. 
"8 Maire, C. R., Paris, 1900, July 9. 
'1' Maire, C. R., Paris, 1900, Dec. 24. 
320 Olive, E. W., Phyto. 1: 139, 1911. 
"1 McAlpine, D., Ag. Vict. B. U: 1891. 

3" Montemartini, Atti d. Ell. Inst. Bot. Univ. di. Pavia, 5: 1897. 
323 Fischer, E., C. Bak. 28: 139, 1910. 
3" Selby, A. D., 0. B., 139: 1903. 
3" South, F. W., W. Ind. Bull. 2: 83, 1911. 

326 Wolff, R., ^cidium pini and sein Zusammenhang mit Coleosporium 
senecionis, Regia, 1876. 

3" Clinton, G. P., J. Myc. 8: 128, 1902.. 

328 Fetch, T., Cirs. and Agr. Jour. Roy. Bot. Gard. Ceylon 5: 89, 1910. 

329 Pennington, L. H., R. Mich. Ac. Sc, 9. 

330 B. P. I. Circ. 35, 8, 1909. 

331 Spaulding Mo. Bot. Gard. R. 17, 53, 1906. 

332 Y. B. U. S. D. Agr. 588, 1907. 

333 V. Schrenk, Cont. Shaw School Bot. No. 14, 45, 1899. 

334 Hedgcock, Sc. 29: 913, 1909. 
336 Mycologia, 157, May, 1910. 

336 Hedgcock, Sc. 29, 913, 1909. 

337 Y. B. U. S. D. Agr. 587, 1907. 

338 Buller J., Ec. Biol, 1: 1, 1905. 

339 Spaulding in Mo. Bot. Garden Report, No. 17. 
3« See Indian Forestry, 36: 559-562, 1910. 

3" Scholz Verhandl. K. K. Zool. Bot. Gesell. Wien. 47; 541-557, 1897. 
3" Vermont Agricultural Experiment Repor. 342-347. 
313 Plowright, C. B., B. M. S. Trans. 90: 1904. 
3" Y. B. U. S. D. Agr. 587, 1907. 
3« Lagerheim, G. J. Myc. 7: 44. 



FUNGI IMPERFECTI (p. 64) 

In the preceding pages it has been repeatedly evident that one 
species of fungus may have two, even several different types of 
spores; in the Erysiphales the perithecial form and the conidial; 
in the Peronosporales oospores and conidia; in the Sphseriales the 
ascigerous form and several conidial forms; in the Basidiomycetes 
the basidial form and various conidial forms; in the Uredinales 
spring and summer stages and teliospores. In comparatively 
few instances among the many thousand species of fungi are all 
of the different spore forms belonging to the species known to 
man. In very many cases the lower or conidial forms are known 
without any higher spore form (ascigerous, basidial, or sexual form), 
being known to be genetically connected with them, though it seems 
very probable, reasoning by analogy, that these conidial forms 
really constitute part of the life cycle of some fungus which em- 
braces also a higher form of spore. It is probable, indeed certain, 
that some of these conidial forms at present possess also higher, as 
yet unknown, forms of fructification. It is likewise probable that 
in many cases the conidial form, though it does not now possess 
any higher spore form, did in its not remote phylogeny possess 
such forms; indeed that all of them are phylogenetically related to 
fungi which produced one of the higher types of spores. 

In some cases even in the absence of the higher spore it is possible 
to refer the fungus to its proper order as for example is the case 
with the conidial forms of the Peronosporales, the summer or spring 
forms of the Uredinales, or the Oospora forms of the Erysiphales. 

Regarding many thousands of other conidial forms such refer- 
ence is impossible or hazardous, since from the conidial form the 
form of the higher spore can be inferred with only a small degree of 
accuracy or not at all. For example, the conidial form known as 
GlcEosporium in the higher form of some of its species proves to be 
a Glomerella, in other cases a Pseudopeziza; some Fusariums 
prove to belong to the life cycle of Nectria, others to that of Neocos- 
mospora, etc. 

475 



476 THE FUNGI WHICH CAUSE PLANT DISEASE 

In plant pathology and in systematic mycology it becomes 
necessary to classify, for convenience of reference and designation, 
these multitudinous conidial forms of which the higher spore 
form is as yet unknown, which may exist now or which may have 
existed only in the more or less remote past. From analogy it 
is probable that most of them pertain to the Ascomycetes, though a 
few may find place among other classes. 

This whole group of forms, which is characterized chiefly by the 
imperfection of our knowledge of them, is classed together under 
the name Fungi Imperf ecti. 

The Fungi Imperfecti are in a temporary way divided into 
orders, families, genera and species as are other fungi, with full 
recognition of the fact that future research will result in many 
cases in the disclosure of higher spore forms and the consequent 
removal of species to their proper place in the general scheme of 
classification. 

Recognizing the tentative nature of the genera in the Fungi 
Imperfecti these are spoken of as "form-genera." 

Pathologically, the Fungi Imperfecti are of high importance, often 
occurring on leaves, stems, fruit, wood, bark, etc., as active parasites, 
though very many are also saprophytes. Upon leaves they are 
particularly common causing diseased areas known as "leaf spots." 

The Fungi Imperfecti display three principal types of fructifi- 
cation, pycnidia, acervuli and hyphae. 

Pycnidia are more or less spherical, hollow sporocarps on the 
inside of which conidia are borne on stalks (conidiophores) arising 
from the base or base and sides. Figs. 349, 354. The pycnidium 
may be of various colors though it is most commonly black or dark; 
it may be superficial or imbedded, and with or without a beak 
(rostrum). The opening for the escape of the spores (ostiole) may 
be narrow, or wanting or it may be very large, round, irregular, 
etc. The walls vary from extremely delicate to very thick, smooth 
or variously provided with hairs, spines, etc. 

As need arises, it is common to speak of micro-pycnidia, and 
macro-pycnidia. Pycnidia with very small spores are sometimes 
called spermogonia especially if the spores do not germinate, a cus- 
tom to be deprecated. 

The acervulus may be regarded as a pycnidium without its wall. 



THE P^UNGl WHICH CAUSE PLANT DISEASE 477 

It consists of a close bed of short conidiophores. Figs. 371, 379. 
Acervuli may be small or large, subepidermal, subcortical or super- 
ficial and may or may not be provided with hairs (setae) Fig. 370, 
of various kinds. An acervulus with a well marked basal stroma 
is known as a sporodochium. Fig. 435. If the sporodochium stalk 
is markedly developed the structure becomes a coremium. It is 
sometimes quite difficult to distinguish between a pycnidium 
with an extremely large ostiole, or one with a very thin wall, and 
the acervulus. For such purposes thin longitudinal sections are 
most useful. 

Hyphae are conidiophores which grow free for some distance 
above their supporting substratum and in more loose form than in 
the acervuli, so that the terminal parts at least stand out as sep- 
arate threads. Figs. 383, 384, 396, 410. 

The hyphae may be simple and short, or long and much branched. 
When the hyphse are very short and closely crowded to form a 
sporogenous cushion the condition of an acervulus is approached 
and confusion arises. 

The conidia borne in the pycnidia, acervuli or on the hyphse are 
of as various forms and types as is well conceivable and are made 
the chief basis for subdivision of orders into form-genera. They 
may be simple or compound, of almost any color, and may be borne 
in bisipetal succession in chains, or solitary, or in groups at the 
apices of the conidiophores. 

The following scheme of Saccardo presents the confessedly 
artificial groups into which conidia may for convenience be divided. 

Scheme of Spore Sections. 

Amerosporso: spores 1-ceIIcd, not stellate, spiral or filiform. 

Hyalosporse: spores hyaline or clear, globose to oblong, continuous. 

Phceosporse: spores dark, yellow to black, globose to oblong, con- 
tinuous. 
Didymosporse : spores, 2-celled. 

Hyalodidymse: spores hyaline, 2-celled. 

Pha^odidymse : spores dark, 2-celled. 
Phragmosporae: spores 3 to many-celled by cross septa. 

Hyalophragmiae: spores hyaline, 3 to many-celled. 

PhaBophragmise: spores dark, 3 to many-celled. 



478 THE FUNGI WHICH CAUSE PLANT DISEASE 

Dictyosporse : spores septate, both crosswise and lengthwise, i. e., 
muriform. 
Hyalodictyse: spores hyaUne, muriform. 
Phaeodictyse: spores dark, muriform. 
Scolecosporse : spores needle-shaped to filiform, continuous or septate. 
Helicosporae: spores spirally twisted, hyaline or dark, continuous or 

septate. 
Staurosporae: spores stellate or radiate, hyaline or dark, continuous 
or septate. 

The mode of bearing spores and the color of the fungus both of 
which it is seen are made the basis of classification have been shown 
by Stevens and Hall ^ and others ^ to depend largely on environ- 
ment, while the septation of the spores, also a fundamental char- 
acter in present classification, depends often on the age of the 
spores or on other factors. Many spores are unicellular until 
germination begins but then become typically 2-celled; e. g., 
Gloeosporium, Such conditions have led to much inaccuracy in 
description and doubtless to undue multiplication of form- 
species. 

It has been quite customary, probably to some extent excusably 
so, to describe as new a form-species when no form-species pre- 
viously described for the same host or its near botanical kin could 
be regarded as identical with it. Thus a Septoria found on Vitis 
would ordinarily be regarded as new unless some of the Septorias 
already described on some of the Vitacese seemed to be the same, 
even though indistinguishable from dozens of Septorias on other 
families of plants. This course has led to enormous multiplica- 
tion of so-called species in these form-genera giving rise to such 
form-genera as Septoria, Cercospora, and Phyllosticta with species 
numbering more than 900, 500, 800, respectively. 

The condition is much as is depicted by Cobb:' "Is a fungus 
species newly found on a peach? Call it new and name it pruni. 
Same genus on the grape — name it ampelinum. On the apple? 
New, call it mali. On banana? Christen it musse. What next? 
Sparrow in a pear tree. Passer pyri?" 

Many of the form-genera are purely artificial — not at all well 
founded, e. g., Phoma is separated from Phyllosticta only by the 
supposed inability of the latter to grow on structures other than 



THE FUNGI WHICH CAUSE PLANT DISEASE 479 

leaves, a distinction which has been shown to be quite untenable." 
It is evident that much careful study by cultures and cross in- 
oculations is needed to reveal the true status in these Fungi. 

Since the conception of species is here most loose the form species 
given below must be regarded as purely tentative. The names are 
to serve merely as handles for convenience in treating of the 
various parasites and in only comparatively few instances do 
they signify that they are really species. In many cases forms 
appearing under two or more names may prove eventually to be 
identical while in other cases forms may need to be su]> 
divided. 

Key to Orders of Fungi Imperfect! 

Conidia produced in pycnidia 1. Sphseropsidales, p. 479. 

Conidia not in pycnidia 

Hyphse innate within the matrix 2. Melanconiales, p. 537. 

Hyphse somewhat superficial, often floccose 3. Moniliales, p. 564. 
Conidia or other special reproductive cells 

unknown 4. Mycelia sterilia, p. 659. 

The Sphaeropsidales 

Conidia in pycnidia which open by pores or slits, superficially 
resembling the perithecia of the Ascomycetes. 

The Sphffiropsidales are preeminently leaf-spotting fungi though 
many of them grow on fruit or stems causing blight, rot, cankers 
etc. The vast majority are saprophytes or parasitic on tissues of 
weak vitality, but not a few are active parasites. 

Key to Families of Sphaeropsidales 

Pycnidia globose, conic, or lenticular 
Pycnidia membranous, carbonous or 

coriaceous, black 1- Sphaerioidaceae, p. 480. 

Pycnidia fleshy or waxy, light colored. 2. Nectrioidaceae, p. 526. 
Pycnidia more or less dimidiate, irregular 

or shield-shaped, black 3. Leptostromataceae^ p. 528. 

Pycnidia cup-shaped or patelliform, black. 4. Excipulaceae, p. 533. 



480 THE FUNGI WHICH CAUSE PLANT DISEASE 



The Sphserioidaceae (p. 479) 

Pycnidia globose, ovate, or clavate, leathery to carbonous, 
black or dark brown, opening by a pore, superficial, erumpent or 
covered; stroma present or absent; conidia variable in form, 
color, and division. 

The family is subdivided according to its spores as indicated 
below. 

Key to Sections op Sphaerioidaceae 

Conidia globose to elongate, straight or 
falcate, 1 to many-celled 
Conidia 1-celled, globose, ovate or elon- 
gate I. Amerosporae. 

Conidia hyaline 1. HyalosporaB, p. 480. 

Conidia colored 2. Phaeosporae, p. 500. 

Conidia 2-celled, ovate to elongate. ... II. Didymosporae. 

Conidia hyaline 3. Hyalodidymae, p. 505. 

Conidia colored 4. Phaeodidymae, p. 509. 

Conidia 3 to many-celled, by transverse 

septa, elongate III. Phragmosporae. 

Conidia hyaline 5. Hyalophragmiae, p. 513. 

Conidia colored 6. Phaeophragmiae, p. 514. 

Conidia muriform, ovate to elongate. . IV. Dictyosporae. 

Conidia hyaline 7. HyalodictyaB. 

Conidia colored 8. Phaeodictyae, p. 516. 

Conidia filiform, 1 to many-celled, hyaline 

or colored V. 9. Scolecosporae, p. 517. 

Conidia cylindric, spirally coiled, 1 to 

many-celled, hyaline or colored VI. 10. Helicosporae. 

Conidia stellate, 1 to many-celled, hyaline 

colored VII. 11. Staurosporae. 

Sphaerioidaceae-Hyalosporae 

Spores hyaline, 1-celled, spherical, elliptical or long. 

Key to Genera of SphaerioidaceaB-HyalosporaB 

Stroma none; pycnidia separate. 
Pycnidia smooth 
Conidia borne singly 



THE FUNGI WHICH CAUSE PLANT DISEASE 481 

Conidia unappendaged 
Pycnidia free in tlie substratum; sub- 
iculuin none 
Pycnidia not beaked, oi^ening by a 
pore, or irregularly 
Not growing on other fungi 
Pycnidia opening by a regular pore 
Pycnidia more or less sunken in the 
substratum 
Pycnidia globose, etc. not spindle- 
shaped 
Pycnidia borne on dark colored 
spots, or on wood, globose 
Conidiophores simple or nearly 
so 
Pycnidia rather large 
Pycnidia at first covered, 
then erumpent 
Spores under 15 M 

On leaves only 1. Phyllosticta, p. 483. 

Not on leaves 2. Phoma, p. 490. 

Spores over 15 M 3. Macrophoma, p. 493. 

Pycnidia from the first super- 
ficial 4. Aposphseria, p. 494. 

Pycnidia very small, closely 
aggregated on dark spots 

on the leaf 5. Asterostomella. 

Conidiophores branched 6. Dendrophoma, p. 494. 

Pycnidia scattered, superficial, 
circular, conidia elongate or 

cyhndric 7. Crocicreas. 

Pycnidia globose ; conidiophores 

circinate 8. Pyrenotrichum. 

Pycnidia horizontal, free, cylin- 

dric 9. Glutinium. 

Pycnidia opening irregularly, or 
operculate 

Spores globose 10. Mycogala. 

Spores elongate or ellipsoid 

Pycnidia operculate 11. Piptostomum. 

Pycnidia opening irregularly 



482 THE FUNGI WHICH CAUSE PLANT DISEASE 

Spores pointed 12. Sclerotiopsis. 

Spores blunt 13. Plenodomus. 

On Erysiphacese 14. Cicinnobolus, p. 494. 

Pycnidia beaked 15. Sphaeronema, p. 494. 

Pycnidia on a subiculum 
Conidia ovate or elongate 
Subiculum of simple hyphae 

Pycnidia free 16. Byssocystis. 

Pycnidia sunken in the subiculum. . 17. Chaetophoma, p. 495. 

Subiculum radiate 18. Asteroma, p. 496. 

Conidia Y-shaped 19. Ypsilonia. 

Conidia appendaged 20. Neottiospora. 

Conidia in chains 
Conidial chains separate and simple ... 21. Sircoccus. 
Conidial chains connected, often form- 
ing a net 22. Pecia. 

Pycnidia appendaged or hairy 
Appendages simple 
Pycnidia with short simple tubercles; 

conidia irregular in outline 23. Muricularia. 

Pycnidia with long bristles; conidia 
regular 
Bristles septate, usually covering the 
entire pycnidium, conidia cylin- 

dric fusoid, usually curved 24. Vermicularia, p. 496. 

Bristles usually only at the apex; 
conidia ovate, elongate or cylin- 

dric, straight 25. Pyrenochaeta, p. 497. 

Appendages stellate at the apex 26. Staurochaeta. 

Pycnidia stromatic, superficial or sunken 
Pycnidia single on the stroma 
Pycnidia with a single chamber 

Conidiophores filiform 27. Phomopsis, p. 493. 

Conidiophores indistinct or absent 

Stroma indistinct 28. Plenodomus. 

Stroma rather well developed 29. Sclerophoma. 

Pycnidia typically with more than one 

chamber 12. Sclerotiopsis. 

Pycnidia with well developed stroma, free 
or buried 
Pycnidia with separate mouths 



THE FUNGI WHICH CAUSE PLANT DISEASE 483 

Pycnidia single on the stroma 30. Dothiopsis. 

Pycnidia several on each stroma 
Conidia separate from each other 
Pycnidia scattered irregularly 
Stroma sharply defined, globose, etc. 
Pycnidial chambers appearing as 

enlargements from without ... 31. Anthracoderma. 
Pycnidial chambers not as above 
Stroma valsoid 
Conidia straight 

Conidia large, fusiform 32. Fusicoccum, p. 498. 

Conidia small, ovate, clavate or 
cylindric 
Conidia ovate or clavate, very 

small 33. Cytosporella, p. 498. 

Conidia larger, ovate, or elon- 
gate 
Pycnidia superficial or sub- 
superficial 

Conidiophores simple 34. Dothiorella, p. 499. 

Conidiophores branched. ... 35. Dothiorellina. 

Pycnidia deep seated 36. Rabenhorstia. 

Conidia allantoid 37. Cytospora, p. 499. 

Stroma pulvinate 38. Fuckelia, p. 500. 

Stroma indefinite, on black spots on 

the host plant 39. Placosphseria. 

Pycnidia regularly arranged on the 

stroma around a sterile center. . . 40. Lamyella. 

Conidia adhering basally in fours 41. Gamosporella. 

Pycnidia on each stroma with a com- 
mon ostiole 
Stroma globose or flask-shaped; conidia 

curved 42. Torsellia. 

Stroma conic-truncate, conidia elongate 

cylindric, straight 43. Ceuthospora, p. 500. 

Stroma thin, effuse; conidia curved to 

allantoid 44. Plagiorhabdus, p. 500. 

Phyllosticta Persoon (p. 481) 
Pycnidia immersed, erumpent or with the beak piercing the 



484 



THE FUNGI WHICH CAUSE PLANT DISEASE 



epidermis, lenticular to globose, thin membranous, opening by 
a pore; conidia small, ovate to elongate, continuous, hyaline or 
green; conidiophore short or almost obsolete. On leaves. 

In part=Guignardia, Valsonectria, Mycosphaerella. 

The genus is a very large one of some eight hundred forms, few of 
which have been adequately studied. It differs from Phoma only in 
that it is foliicolous while Phoma is caulicolous, a distinction which 




Fig. 335. — P. solitaria. 1, section through apple; 4, spores 
from apple blotch showing appendages; 6-7, germinating 
spores; 9, mycelium from corn-meal cultures. After Scott 
and Rorer. 

is not consistently maintained and which is untenable for generic 
limitation (see p. 478). 

The fungus produces leaf spots by killing or weakening the 
leaf tissue with its mycelium. The spots are circular or subcircular, 
unless rendered angular by obstruction by veins, and the pycnidia 
may usually be seen with a lens in old spots unless the color of the 
leaf forbids. Similar effects follow on fruits. 

P. ampelopsidis E. & M. on Ampelopsis is probablj'^ identical 
with P. labruscae =Guignardia bidwellii. See p. 238. 

P. bellunensis Mart, on elm = Mycosphaerella ulmi. See p. 249. 

P. brassicae (Carr.) West on cabbage, etc. = Mycosphaerella bras- 
siaecola.^ See p. 249. 

P. labruscaB Thiim. on the grape =Guignardia bidwellii. See 
p. 238. 



THE FUNGI WHICH CAUSE PLANT DISEASE 485 

P. tabifica Prill is perhaps identical with Mycospharella tabifica, 
though Potebnia'' questions this. See p. 247. 

P. maculiformis (Pers.) Sacc. on chestnut = My cosphaerella 
maculiformis. See p. 249. 

P. solitaria E. & E.^' ^ 

Perithecia minute, immersed, the ostiole only erumpent; conidia 
broadly elliptic, 8-10 x 5-6 n, surrounded by a mucilaginous sheath. 

It is the cause of apple fruit blotch and of cankers and leaf spots. 
On the fruit it was first reported by Clinton ^ in 1902. The fruit 
spots show a characteristic fringed appearance owing to the 
imequal advance of the mycelium which is limited to the outer- 
most fruit cells. In the fruit the pycnidia develop subepidermally. 




Fig. 336. — P. solitaria. 1-month-old colony on apple agar. After 
Scott and Rorer. 

The fungus was grown in pure culture and its identity on twig, 
leaf and fruit was shown by cross inoculation. 

P. persicae Sacc. is common on peach leaves. 

P. piricola Sacc. & Speg. is foimd on apple and pear. 

P. limitata Pk.^° is reported as the cause of an apple leaf spot. 

Spots round minute, 2-6 mm., brown or reddish; pycnidia epiph- 
yllous, black, few, punctiform; spores ellipsoid, 7-8 x 4 ju. P. mali 
P. & D. occurs on apple and pear. 

P. pirina Sacc.^^ 

Spots variable; pycnidia epiphyllous, punctiforjn, lenticular, 
100-130 n, context loosely cellular, brown; conidia ovoid to 
ellipsoid, 4-5 x 2-2.5 ijl. 

This was long regarded as the chief factor causing the common 
leaf spot on the apple and pear. Recent work throws doubt on this. 



486 THE FUNGI WHICH CAUSE PLANT DISEASE 

P. circumscissa Cke. 

Amphigenous; spots orbicular, reddish-brown, at length de- 
ciduous; pycnidia scattered, minute; conidia elliptic, 8 x 2 )u. 

Spots and shot holes are formed on drupaceous hosts. 

P. prunicola Sacc.^- 

Spots subcircular, epiphyllous, sordid-brownish or ochraceous, 
margin subconcolorous; pycnidia scattered, punctiform; conidia 
ovoid to ellipsoid, 5 x 3 ju. 

It is foimd on Prunus, causing leaf spots in Europe, America 
and Australia. Scurf is also produced on apple bark. 

P. armenicola Far. is associated with an apricot fruit disease. 

P. grossulariae Sacc. grows on Ribes grossularia. 

P. fragaricola D, & R. is widespread in Europe on the strawberry. 

P. vitis Sacc. and P. succedanea (Pass.) All. are found on grape 
in Europe. 

P. vialae R. & G. also parasitizes the grape. 

P. bizzozeriana Mass. in Hungary produces a grape disease 
superficially resembling black rot.^^ 

P. putrefaciens Sh. occurs on cranberry. 

P. oleae Pet. and P. insulata Mont, cause leaf spots on the olive. 

P. cannabinis Kirch forms spots on hemp leaves; 

P. humuli Sacc. & Speg. on the hop. 

P. bataticola E. & M. Pycnidia scattered, minute, black; spots 
small rounded, whitish with a purple margin; conidia ellipsoid, 
5 X 2iu. Leaf spots are produced on the sweet potato. 

P. nicotiana E. & E. 

Spots brown, reddish, zonate; pycnidia 200 n, black; conidia 
3.5-5 X 1.5 jLt. It causes leaf spots of tobacco;^* 

P. tabaci Pass, also occurs on Nicotiana. 

P. medicaginis (Fcl.) Sacc. occurs on alfalfa; ^^ 

P. japonica Miy. and P. miuria Miy. parasitize rice. ^^ 

P. betae Oud. 

Spots grayish-ochre, large and irregular; pycnidia epiphyllous, 
minute, densely clustered, browTiish, subimmersed; conidia elliptic, 
5-6 X 3 iu. 

It is mentioned by Stewart ^'^ as the cause of leaf spots of beets. 

P. malkoffi Bub. causes cotton leaf spots in Bulgaria. 

P. cofifeicola Del. and P. comoensis Del. are on coffee; 



THE FUNGI WHICH CAUSE PLANT DISEASE 487 

P. cinnamoni Del. on cinnamon leaves; 

P. hevea Ziinm. on Para rubber. 

P. hortorum Speg.^^' ^^ 

Spots circular, indefinite, fulvous, gray in the center, amphig- 
enous, at last falling away; pycnidia in the center of the spot, 
minute, 80-90 n, globose-lenticular, thin, membranous, dull 
f usco-olivaceous ; conidia elliptic to ovoid, rounded at the ends, 
4-6 X 2-2.5 M- 

It produces spots on leaves and fruit of egg plant in Europe 
and America. 

P. chenopodii Sacc.^° 

Spots irregular, scattered or confluent, ochraceous, fuscous 
margined; pycnidia lenticular, punctiform, 50 n; conida oblong- 
elliptic, 5 X 3 /x. A leaf spot is produced on spinach. 

P. apii Hals.^^ forms brown spots on leaves of celery; pycnidia 
punctiform, black; conidia elliptic to ovate oblong. 

P. phaseolina Sacc. 

Spots irregularly scattered, subcircular, 2-10 mm., deep rusty 
brown, becoming lighter in center and darker margined; pycnidia 
scattered, 70-90 n; conidia ovoid oblong, 4-6 x 2-2.5 ju. 

It causes spotting of bean and cowpea.^^^ 

P. cucurbitacearum Sacc. 

Spots epiphyllous or amphigenous, sordid, whitish ; pycnida punc- 
tiform, 80-100 fx, lenticular; conidia oblong, 5-6 x 214 M, curved. 

On muskmelon, cucumbers and other cucurbs, spotting the 
leaves. ^'' -'--^ 

P. citrullina Chester "^ is also reported on melons, ^^^ 

P. maculicola Hals.^^ produces spots in Dracsena and related 
plants. 

P. hedericola Dur. & M. and P. hederacea (Arc.) All. cause 
spots on Hedera leaves,-^' ''^^ 

P. rosae Desm. and P. argillaceae Bres. occur on roses. 

P. rosarum Pass, causes a black spot on roses in New South 
Wales. 

P. althaeina Sacc.^^ 

Spots irregular, with a dark browTi margin; pycnidia few, 
lenticular, 90 /x, ochraceous; conidia ovate-oblong, 6-7 x 3-4 /i- 

On hollyhock in Italy, France and America. 



488 THE FUNGI WHICH CAUSE PLANT DISEASE 

P. idaecola Cke. forms spots on cultivated species of Sida and 
Hibiscus. 

P. dianthi West, grows on Dianthus leaves. 

P. primulaecola Desm. occurs on Primula leaves.^^ 

Amphigenous; spots large, white, light margined; pycnidia epiph- 
yllous, numerous, prominent, globose, black; conidia subglobose. 

P. violae Desm.-^' ^ 

Amphigenous, spots white, round; pycnidia numerous, minute, 
brown; spores minute, subcylindric, 10 fi long. 

Common, causing leaf spots on pansy and violet. 

P. hydrangeae E. & E.^^ 

Spots 1.5-1 cm. or more, rusty brown, margin narrow, raised, 
at first shaded with purple; pycnidia epiphyllous, lenticular, 
100-115 m; conidia oblong, 10-12 x 2.5-3.5 ii. 

On Hydrangea causing leaf spots. 

P. syringae West, is common on lilac. 

P. halstedii E. & E. 

Amphigenous, spots roundish, reddish-brown, \i-V/i cm. con- 
centrically zonate, pycnidia few, lenticular, 100-150 /x, immersed; 
conidia broadly fusoid-oblong, 15-20 x 5-7 ^u. Causing a leaf spot 
of the lilac. 

P. cruenta (Fr.) Kick. 

Spots subcircular, reddish, becoming paler in the center; pycnidia 
gregarious or scattered, globose-lenticular, dark olivaceous; conidia 
ovate-oblong, 14-16 x 5.5-6.5 /x; conidiophores, cylindric, 10-12x4/i. 

It causes leaf spots of cultivated Solomon's Seal. 

P. cyclaminis Brun. occurs on cyclamen; 

P. digitalis Bell on digitalis. 

P. chrysanthemi E. & D.^e 

Spots purplish-brown, pycnidia 80-100 ju; conidia 4-5 x 2.5-3 ju. 

It causes leaf spots on cultivated chrysanthemums. 

P. leucanthemi Speg. is occasionally found in spots of chrysan- 
themum leaves. 

P. richardiae Hals.-^ is common as a leaf spotter of the calla 
lily but has not been satisfactorily descril)ed. 

P. opuntiae Sacc. & Speg. occurs on various of the Cactaceae; 

P. liliicola Sacc. on lily; 

P. vincae minoris B. & K. on Vinca minor; 



THE FUNGI WHICH CAUSE PLANT DISEASE 489 

P. pteridis Hals, causes blighting of cultivated Pteris; "^ 

P. narcissi Aderh. of narcissus. ^° 

P. cavarae Trinch. produces white spots on leaves of Anthurium.^^ 

P. dracaenae causes spots on Dracsena leaves. 

P. funckia Hals. Pycnidia 75-150 ix, straw colored. 

The cause of leaf spots of cultivated Funkias.^'^ 

P. dammarae is found on Dammara in Italy; 

P. nobilis Thum. on Laurus. 

P. ulmicola Sacc. 

Spots indefinite, ochraceous, margin concolorous; pycnidia gre- 
garious, punctiform, 70-80 ijl, lenticular; conidia oblong ellipsoid, 
6-3 M- It infests elm leaves. ^^ 

P. acericola C. & E^- 

Spots irregular, fuscous, brown margined; pycnidia densely 
scattered on the central part of the spot, subepidermal, flask- 
shaped, dark brown, 120 ju; conidia ovate, 8-9 x 5-6 /jl. 

It causes serious leaf spotting of maples throughout the United 
States. 

P. aceris Sacc. forms small spots on maple leaves. 

P. paviae Desm. 

Spots indeterminate, reddish, lighter margined; pycnidia 
epiphyllous, black; conidia cylindric-elliptic, 11-12 ^ long. It 
is said to be common on J^sculus.^^ 

P. sphaeropsidea E. & E.^^ 

Epiphyllous; spots reddish-browTi, margin lighter, scattered 
or confluent, 1-2 cm.; pycnidia scattered, immersed, punctiform, 
erumpent above, subepidermal; conidia globose to broadly ellip- 
soid, hyaline, 12-15.5 x 8-10 n. 

It causes serious leaf spotting of chestnuts throughout the 
United States. 

P. tiliae Sacc. & Speg. is found on Tilia. 

P. minima (B. & C.) E. is on Negundo. 

P. catalpae E. & M. 

Spots, rounded, brown, 3-6 mm., often confluent; pycnidia 
subcuticular, small, black, scattered, 112 x 84; conidia ovate, 5-7 x 
2.5-4.5 IJL. It causes leaf spots on Catalpa.^"* 

P. magnolias Sacc. causes leaf spots on Magnolia; P. viridis E. & 
K. on ash; P. ilicina Sacc. on the cork oak. 



490 THE FUNGI WHICH CAUSE PLANT DISEASE 

An unidentified species has been reported on watermelon ^^ as 
cause of considerable injury. Halstead mentions also an undeter- 
mined species on oats.-^ Pycnidia 150-250 {j,; spores 12-18 x 
6-7 /i, pyriform. 

Phoma (Fries) Desmaziere (p. 481) 

The genus as at present recorded contains over 1200 forms. 
It is indistinguishable from Phyllosticta (see p. 484) except that 
it is caulivorous. Several species are regarded as conidial forms 
of Diaporthe, Mycosphaerella, etc. 

P. reniformis on grape =Guignardia bidwellii. See p. 238. 

P. albicans Rob. & Desm. on chicory =Pleospora albicans. 
See p. 260. 

P. betae Fr. on beet = Mycosphaerella tabifica. See p. 247. 

P. bohemica Bub. & Kab. on fir tree needles = Rehmielliopsis. 
See p. 276. 

P. ambigua (Nitz.) Sacc. on pear = Diaporthe ambigua. See 
p. 279. 

P. sarmentella Sacc. on hop = Diaporthe sarmentella. See 
p. 279. 

P. persicae Sacc. 

Pycnidia scattered to gregarious, glol^ose lenticular, /e- /b mm. ; 
conidia oblong ovoid, 8-3 x 2 /x, conidiophores cylindro-conical, 
equal in length. 

It produces constriction and death of peach twigs.^^ 

P. mall S. & S.^^' '' 

Pycnidia gregarious, subcuticular, depressed, ostiole erumpent; 
conidia oblong-f usoid, 2-3 x 5-8 /x. 

It attacks the wood of young apple trees and also causes a decay 
of the fruit. 

P. cydoniae Sacc.^^ 

Pycnidia subgregarious, depressed, ostiole obtuse or erumpent, 
conidia elliptic oblong, 8-9 /x long; conidiophores short. 

A form causing rot of quince fruit was provisionally referred 
to this species l^y Halsted. 

P. limonis Thiim. & Boll. P. citri Sacc. and P. aurantiorum 
(Rab.) Sacc. occur on citrous fruits; 



THE FUNGI WHICH CAUSE PLANT DISEASE 491 

P. pomarum Thiim. on pomaceous fruits in Europe. 

P. myxiae Far. is associated with an apricot fruit spot. 

P. omnivora McA. is described as the cause of AustraUan wither 
tip of the orange '^° while to P. citricarpa McA is attributed another 
common Austrahan citrous fruit disease. 

P. mororum Sacc. is on Morus. 

P. tuberculata McA. causes a disease of grape berries in Aus- 
traha."*^ 

P. lophiostomoides Sacc. is common and perhaps parasitic on 
cereals. 

P. hennebergii Kiihn produces brown spots on the glumes of 
wheat and leads to some injury to the grain.'*" 

P. solanicola P. & D.'*^ causes a disease of potato ^^^ stems in 
France. 

P. solani Hals.^^ 

Pycnidia innate, depressed, oblong; conidia oblong. 

On egg plant causing damping-off of seedlings. 

P. subcircinata E. & E. 

Pycnidia black, 70-90 m; conidia 5-6 x 2-2.5 n. 

Spots are produced on bean pods. 

P. sanguinolenta Rost.^^ 

Pycnidia scattered, subglobose; conidia ellipsoid, 4-6 x 1.5-3 
/jl; surrounded by a slime which gives the spore-mass a violet-red 
color. 

As the cause of a rot of carrot roots it has been reported in New 
Jersey. 

P. oleraceae Sacc.''^"^^ 

Pycnidia scattered, globose depressed, papillate, sunken in 
the tissues, 34"/^ mm.; conidia oblong, subcylindric, medially 
constricted, apically obtuse, 5-6 x 2 )u. 

Manns notes this fungus causing a serious cabbage disease in 
Ohio. The pycnidia are sparse on oval sunken diseased areas on 
the stems, and bacterial invasion follows soon in leaves, cam- 
bium and xylem. The cambium is rapidly destroyed and the 
plant collapses. Bos ^^ and Quanjer ^^ have demonstrated the 
pathogenicity of the fungus. 

P. napobrassicae Rost. causes rot of mangolds in Den- 
mark; ^^''^ also recently reported from Canada. ^^ 



492 THE FUNGI WHICH CAUSE PLANT DISEASE 

P. apiicola Speg. is recorded on celery.^- 

P. brassicse Thiim. on cabbage is probably identical with 
P. oleraceae. 

P. roumii Fron. is said to cause a serious cotton disease in 
Africa. ^^ 

P. batatae E. & H.^^ 

Pycnidia blackish, gregarious, immersed; conidia terete, ovoid; 
conidiophores slender. The cause of dry rot of sweet pota- 
toes. 

P. chrysanthemi Vogl. is found on leaves of chrysanthemum 
causing them to wilt. 

P. malvacearum West is noted on European hollyhocks; 

P. devastatrix Berk, on cultivated lobelias ; 




Fig. 337. ^P. olcracea. A, showing pycnidia with spores stream- 
ing out; B, section; C, spores. After Manns. 

P. dahlias Berk, on stems and flowers of Dahlia. 

P. cyclamenae Hals, is given as the cause of Cyclamen leaf spots 
but without ample description. 

P. oleandrina Del. is on the rose, laurel, etc. 

P. pithya Sacc. seems to be parasitic on the fir causing con- 
rtriction and death of twigs. 

P. strobi (B. & Br.) Sacc. is prevalent on white pine in Europe. 

P. strobilinum P. & C. is closely related to the above. 

P. sordida Dur. & M. occurs on Carpinus. 

P. ribesia Sacc. Pycnidia collected, erumpent, spores oblong- 
fusoid, 10 X 33^ iu, hyaline. In branches of Grossularise. 

Several undetermined species have been reported, among them 



THE FUNGI WHICH CAUSE PLANT DISEASE 493 

one on snapdragon,'^'^ another on Clematis roots,''^ and one on ap- 
ple «' 

Phomopsis Saccardo " (p. 482) 

As in Phoma, but with hooked conidiophores. A small genus. 

P. aloeapercrassae Trinch. is reported on scapes and flowers of 
the aloe in Italy. 

P. stewartii Pk. 

Perithecia gregarious, commonly occupying grayish or bro\\'n 
spots, thin, subcutaneous, at length erumpent, depressed, minute, 
V3-V2 mm. broad, black; spores of two kinds, first ; filiform, curved, 
flexuous or uncinate, hyaline, 16-25 x 1-1.5 m, second; oblong or 
subfusiform, hyaline, commonly binucleate, 8-12 x 2-3 m; 
sporophores slender, equal to or shorter than the spores. 

The fungus with its filiform spores only was noted as a parasite 
on Cosmos by Halsted who referred to it as a species of Phlyctaena.^' 
It has been noted in New York by Stewart, ^^ and is destructive 
both in the greenhouse and in the open. 

Macrophoma Berlese & Voglino (p. 481) 

As in Phoma, but the ostiole of the pycnidium not papillate, 
and the pore smaller; conidia over 15 m long; conidiophores sim- 
ple, short or filiform. 

About one hundred seventy-five species. 

M. hennebergii (Kahn) Berl. & Vogl. causes a serious disease 
on wheat in Sweden .^^ 

The fungus which appears in the Uterature as M. curvispora 
Pk. is in reality Gloeosporium malicorticis, see 
p. 542, and that referred to as M. malorum 
is Myxosporium corticolum. See p. 546. 

M. vestita Prill. & Del. attacks cacao in 
Ecuador. ^ ^^ 

M. dalmatica (Thiim.) B. & V. parasitizes the ^^^ sss.Im. curvi- 
olive; M. taxi B. & V. attacks the leaves of ^P°corXr^" ^^' 
Taxus; M. abietis M. & H. is associated with 
a fir disease; M. manihotis Hem. is on cassava; M. ligustica Mag- 
nag on Hydrangeas; M. helicinia Magnag on ivy. 




494 THE FUNGI WHICH CAUSE PLANT DISEASE 

M. reniformis (V. & R.) Car. is reported on grapes in Algiers, 
Italy and Russia. 

Aposphaeria Berkley (p. 481) 

Pycnidia globose, carbonous, with a papillate ostiole, erum- 
pent or superficial; conidia elongate to globose; conidiophores 
very short or absent. 

One hundred species are recognized. 

An undetermined species was found by Stevens -^ in New York 
,and New Jersey in 1892, causing diseased spots on strawberry 
leaves. 

Dendrophoma Saccardo (p. 481) 

■ Pycnidia superficial or subepidermal and erum- 
.pent, carbonous; ostiole papillate; conidia elongate; 
conidiophores branched. 

A genus of some fifty species, chiefly sapro- 
phytes. 

D. marconii Cav. occurs on hemp stems; D. con- Fig. 339.— Den- 
vallariae Cav. on leaves of Convallaria majalis; n^d^iopTor'es 
D. valsispora Penz on living lemon leaves. ^"^^j. ^I'l'^'gl 

Cicinnobolus Ehrenberg is frequently met as a cher. 
parasite on the mycelium of the Erysiphales. 

Macrodendrophoma salicicola on Salix = Physalospora gregaria. 
See p. 252. 

Sphaeronema Fries (p. 482) 

Pycnidia superficial or not, pyriform, cylindric or globose, 
rostrum long; conidia ovate or elongate. 

Some seventy-five species, chiefly saprophytes, have been de- 
scribed. 

S. phacidioides Desm. on clover =Pseudopeziza trifolii. See 
p. 148. 

S. fimbriatum (E. & H.) Sacc^^' ^^ 

Pycnidia globose, 100-200 fx, surrounded by septate, hyaline 





THE FUNGI WHICH CAUSE PLANT DISEASE 495 

hyphse, rostrum, 20-30 ix long, apically fimbriate; conidia globose- 
elliptic, 5-9 /x. 

The fungus grows in the sweet potato producing dark, almost 
black spots in the skin. The tissue below becomes olive-green. 
The dark mycelium is found penetrating 
through and between cells of the dis- 
eased area where numerous olivaceous 
conidia are also present. The elon- 
gated beaks of the pycnidia rise like a 
small forest from the surface of the 
potato. 

In artificial culture the mycelium is 
dark, abundantly septate and with nu- 
merous oil globules. Long multiseptate ., 
conidiophores with light colored tips fiq. 340.— S. fimbriatum; 1, 
arise from the medium. From these pycnidium sending forth 

spores; 2, hyaline conidia; o, 

hyaline conidia are produced, appar- oHve conidia. After Halsted 
ently endogenously. Fig. 340, Oliva- 

ceus, globose to elliptical, Fig. 340, conicUa are formed within the 
medium on branches of the mycelium in much the same manner. 
The pycnidia develop in about nine days after inoculation and the 
conidia are extruded from the fimbriate mouth of the long ros- 
trum. 

Inoculations proved the pathogenicity of the organism, 
typical black rot appearing in about three weeks after infec- 
tion. 

S. adiposum Butler causes a black rot of sugar cane. 

S. pomarum Sh. is on cranberry. 

S. spurium (Fr.) Sacc. on Prunus is often reported as Dematium 
prunastri. 

S. oryzae Miy. is on rice.^® 

Chaetophoma Cooke (p. 482) 

Pycnidia superficial, very small, on a subiculum of interwoven 
hyphse; conidia ovate or elliptic, very small. 
Some forty species, chiefly American. 
C. glumarum Miy. parasitizes rice in Japan. ^^ 



496 THE FUNGT WHICH CAUSE PLANT DISEASE 



Asteroma De Candolle (p. 482) 

Pycnidia very small, globose, erumpent, often on a mass of 
hyphae; conidia ovate or short eylindric. In part =Gnomonia. See 
p.. 274. 

About forty species chiefly parasitic. 

A. padi (D. C.) Grev. on Prunus=Gnomonia padicola. See 
p. 275. 

A. geographicum (D. C.) Desm. occurs on various species of 
Pomacese; 

A. punctiforme Berk, on the rose; 

A. stuhlmanni Hen. on bananas and pineapples in Africa. 

A. codisei All. is said to be a serious parasite of Codiaium.®' 

Vermicularia Fries (p. 482) 

Pycnidia superficial, or erumpent, globose depressed, to globose 
clavate, leathery or carbonous, black, ostiolate or not, beset 
with rather long, stiff, septate, dark colored bristles; conidia 

cylindric-fusoid, often curved. 

Some one hundred thirty 

species, chiefly saprophytes. 

V. dematium (Pers.) Fr. 

Pycnidia erumpent, superficial, 

80-120 fjL, conic, then depressed, 

often confluent, black, spines 

pale at the ends, 150-200 x 5 ju; 

conidia cylindric-elongate, 20 x 

i\S\Sd 4-6 n, apically rounded, curved. 

Fig. 341. -V. dematium. c, a nearly Commonly a Saprophyte, this 
mature "perithecium;" s, spores; fungus Occasionally causes as- 

-"t liypilSB. Al lGP XV66Q. cc -r • 

paragus disease.''^ In Europe it 
is reported as the cause of much loss to the ginseng crop. On 
this plant it produces a stem anthracnose. The fungus was 
isolated and its cultural characters studied by Reed.^^ 

V. trichella Fr. 

P3^cnidia ovate, small, black, spines long, at the apex of the 
pycnidium; conidia fusoid, curved, pointed, 16-25 x 4-5 /x. 





THE FUNGI WHICH CAUSE PLANT DISEASE 497 

On living parts of many fruit hosts, as well as ivy and other 
woody plants.^^ 

V. melicae Fcl. grows on Melica; 

V. microchaeta Pass, on camellia. 

V. circinans Berk.^^' ^^ 

Spots orbicular; pycnidia arranged concentrically, small, setae 
long; conidia oblong, curved, obtuse. 

On onions the fungus appears as small black dots on the scales. 
These later become encircled by rings of black pycnidia. Stone- 
man found no true pycnidium; this would indicate relationship 
of the organism with Volutella rather than with Vermicularia. 

V. varians Due. is described by Ducomet as the cause of a scab- 
like disease of tomato and potato.^^ 

V. subeffigurata Schw. Pycnidia large, scattered, dark, sub- 
elevated; spines unequal. On carnation leaves. 

V. telephii Karst.^^ 

Pycnidia scattered, erumpent, superficial, spherical, dark, 100- 
150 fx; conidia fusoid bacilliform, acutely curved, 
22-32 X 4 /x. 

On leaves and stems of cultivated Sedums. 

V. concentrica Lev. is reported by Halsted -^ |||^ ^ 

as causing unsightly spots on Dracaena. 

V. denudata Schw. A Vermicularia referred 
to as probably this species is reported as dam- S42 — P 

aging to Kentucky blue grass in Dakota.^*^ chaeta berbeiidis, 

V, .... ri 1 • J. J 1 conidiophoro and 

. polygoni-virgmica Schw. is reported by conidia: After Ai- 

Reed & Cooley on rhubarb. i^« l^^'^^^^- 

An undetermined species is reported as injurious to the potato.^^ 

Pyrenochaeta de Notaris (p. 482) 

Pycnidia globose-clavate, erumpent, leathery or carbonous, 
black, bristly, ostiolate; conidia ovate, elongate or cylindric; 
conidiophores branched. 

A genus of some thirty species. 

P. phloxidis Mas. is common just above ground on living stems 
of Phlox causing cankers. 

P. ferox Sacc. is found on potato stems. 

P. oryzae Miyake ^^ occurs on rice in Japan. 



498 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Fusicoccum Corda (p. 483) 

Stroma subepidermal, several-chambered, erumpent, leathery, 
black; conidia fusoid, straight and usually large. 

Some forty species, several of which are regarded as conidial 
forms of Diaporthe and Gnomonia. 

F. veronense Massal on Sycamore and Oak = Gnomonia veneta. 
See p. 274. 

F. viticolum Red. on grape =Cryptosporella viticola. See p. 280. 




Fig. 343. — F. viticolum, compound pycnidium, germinating spores, pa- 
raphyses. After Reddick. 

F. amygdali Del. causes a spot disease of almond twigs in 
Europe. 

F. bulgarium Bub. is described as the cause of a grape disease in 
Austria.^- 

F. perniciosum Briosi & Farm, on chestnut =Melanconis 
modonia Tul. See p. 281. 

Cytosporella Saccardo (p. 483) 

Stroma tuberculate or cushion-form, immersed, then erumpent, 
leathery, black, lighter within; conidia clavate or ovate, usually 
quite small. Some twenty-five species. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



499 



C. cerei, Poll, is on Cereus; 

C. citri Maynag. on oranges; 

C. damnosa Pet. on pine; all in Italy. 

C. persicae Schw. is reported on young peach branches. 

Cytospora Ehrenberg (p. 483) 

Stroma superficial or erumpent, tubercular, with irregular 
chambers; conidia elongate allantoid. 
Ascigerous forms belonging to Valsa are 
known. 

Some two hundred species, chiefly 
saprophytes. 

C. palmarum Cke. is on palms. 

C. ceratophora Sacc. is the suspected 
cause of a blight of Japanese chestnuts.^^ 

C. acerina Aderh. causes disease of Acer in Europe. ^'^ 

C. sacchari Butler is found on sugar cane in Bengal. 

Dothiorellina Bubak with the one species D. tankoffiii Bub. has 
recently been described as the cause of disease of the mulberry. ^^^ 




Fig. 344. — Cytospora. Sec- 
tion through a stroma. 
After Chester. 



Dothiorella Saccardo (p. 483) 

Pycnidia erumpent, on a stroma, leathery, ostiole papillate or 
not; conidia ovate or elongate. 

Some seventy species, chiefly saprophytes. 

D. ribis (Fcl.) Sacc, on a wide range of hosts =Diaporthe stru- 
mella. See p. 279. 




Fig. 345. — D. mori. A'', section of stroma, 0, conidio- 
phores and conidia. After Allescher. 

D. mori Berl. and D. populi Sacc. are perhaps parasitic on Morus 
and Populus respectively. 

An unidentified species is reported by Duggar on currant as 
the cause of cane blight. Inoculations using the conidia have 
produced the disease. See also p. 283. 



500 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Fuckelia Bonordin (p. 483) 

Stroma erumpent, globose-pulvinate, substipitate, dark without, 
lighter within, with several angular pycnidial locules; conidia 
elliptic. 

A single species F. ribis Bon. on currants in Europe is a conidial 
form of Cenangium vitesia. See p. 151. 

Ceuthospora Grevielle (p. 483) 

Stroma coalescing, erumpent, cushion-shaped, leathery, many- 
chambered, all chambers opening by a common pore; conidia 
elongate cylindric, mostly straight. 

Some twenty-five species, chiefly saprophytes. 




Fig. 346.— C. cattlcyaj, a 
p y c n i d i u m. After 
Delacroix. 




Fig. 347. — Plagiorhabdus 
oxycocci on cranberry. 
After Shear. 



C. cofifeicola Del. is of questionable parasitism on coffee; 
C. cattleyae Sacc. & Syd. on orchids. 

Plagiorhabdus oxycocci Shear has been reported on cran- 
berry. ^^^ 

Sphaerioidaceae — Phaeosporae (p. 480) 

Conidia 1-celled, dark, globose, ovoid or oblong. 



Key to Genera of Sphaeropsioidaceae — Phaeosporae 

Pycnidia separate >> 

Pycnidia without mycelium or subicle 
Pycnidia smooth, not hairy 
Conidia in chains, globose 1. Sirothecium. 



THE FUNGI WHICH CAUSE PLANT DISEASE 501 

Conidia not in chains 
Pycnidia sessile, splioroid 

Pycnidia beaked 2. Naemosphaera. 

Pycnidia not beaked 

Conidia spindle-form, with 

both ends light colored . . 3. Hypocenia. 
Conidia globose to elliptic 
Pycnidia opening irregu- 
larly 4. Harknessia. 

Pycnidia opening bj' a regu- 
lar ostiole 
Conidia large, ovate to 

elliptic 5. Sphaeropsis, p. 501. 

Conidia very small, glo- 
bose to ellipsoid. ... 6. Coniothyrium, p. 503. 

Pycnidia stipitate, clavate 7. Levieuxia. 

Pycnidia hairy or setose 8. Chaetomella. 

Pycnidia with distinct mycelium or 
subicle 
Pycnidia astomous, in a dark subicle. . 9. Capnodiastrum. 

Pycnidia perforate 10. Cicinnobella. 

Pycnidia cespitose or in a stroma 

Pycnidia in dense erumpent clusters 11. Haplosporella. 

Pycnidia not as above, in a definite 
stroma 
Stroma applanate or effuse, foliicolous. 12. Discomycopsis. 
Stroma dot-like, discoid or hemi- 
spheric 

Stroma dot-like, immersed 13. Melanconiopsis. 

Stroma discoid to hemispheric 

Stroma discoid; spores large 14. Nothopatella. 

Stroma pulvinate; spores minute, 

catenulate 15. Cytoplea. 

Stroma hemispheric ; pycnidia 

circinate 16. Weinmannodora. 

Sphaeropsis Leveille 

Pycnidia immersed, erumpent, globoid, black, leathery, mem- 
branous, with the ostiole papillate; conidia ovate or elongate, 
conidiophores rod-like. 



502 



THE FUNGI WHICH CAUSE PLANT DISEASE 



About two hundred species several of them important plant 
pathogens. 

S. malorum Pk. 6°' -• "^"^^ 

Mycelium sooty-brown; pycnidia erumpent, usually surrounded 
by broken epidermis, apically somewhat depressed; conidia oblong 
elliptic, brown, usually about twice as long as broad, 22-32 x 10-14 
H, varying in size with host and part attacked. 

On apple, pear, quince, hawthorn; on twigs causing canker or 
blight; on fruit causing rot and on leaves causing spots'. 





'; "■■■ ?' 


?k 




>; 




' 


■ii 






t 




.^ 






i.&>-L'4 


!' 





Fig. 348. — S. mahjium, /*, dark colored mycelial 
threads among the cells of the fruit; d, a 
pycnidium, which has pushed through the epi- 
dermis, c, and is giving off dark colored spores, e; 
B, mature spores germinating in water. After 
Longyear. 



This is one of the common causes of pomaceous fruit rots and 
of leaf spot in the United States. Its occurrence in leaf spots was 
noted in 1898,^^ and in 1902 Clinton ^'^ recognized it as their cause. 
Cultures were obtained from diseased leaf spots bj^ Scott & Rorer ^^ 
and by inoculations the ability of the fungus to cause spots was 
definitely proved. 

This fungus was reported by Paddock ^^ as the probable cause 
of apple twig blight and canker and cross inoculation between 
twigs and fruit proved the identity of the fungus on these two parts. 

The mycelium is very dark or olivaceous and abounds in the 
rotten pulp of affected fruit, also in diseased bark, and is even 



THE FUNdl WHICH CAUSE PLANT DISEASE 503 

present in wood though extencUng Init si)aringly into woody 
tissue. 

A pycnidial fungus agreeing with S. malorum morphologically 
has been shown by Shear ^- to be a conidial form of the aseigerous 
fungus Melanops ( = Botryospliseria), see p. 284. 

S. pseudodiplodia (Man.) G. & M. **^' ^^ causes an apple disease 
in Europe. 

S. mori Berl. parasitizes Morus; 

S. ulmiS. &R. the elm; 

S. magnoliae Magnag. the Magnolia in Italy; 

S. japonicum Miy. rice in Japan. ^^ 

S. vincae S. & W. 

Pycnidia gregarious or scattered, globose, immersed, black, 
small, 260-300 At; ostiole papillate, erumpent; conidia ovate, 
ovate-oblong or subpyriform, 17-28 x 10-14 n. On Vinca.-^'* 

Many other forms are recorded on various hosts but their 
parasitism is questionable. 

Coniothyrium Corda (p. 501) 

Pycnidia subcortical, erumpent or not, globose or depressed, 
ostiole papillate, black, leathery to car]3onous; spores small, 
ellipsoid, conidiophore reduced or absent. 

More than one hundred fifty species. 

C. pyriana (Sacc.) Shel. is common on apple leaf spots but is not 
regarded as their cause.^ 

C. concentricum (Desm.) Sacc. occurs on Yucca, Dracsena, etc. 

C. tumefaciens Gus.^'' is described as the cause of a rose canker. 

C. melastorum (Berk.) Sacc.^^ is on sugar cane. 

C. fuckelii Sacc.^^ 

Pycnidia superficial, scattered, dark, 180-200 n, globose- 
depressed; conidia numerous, globose to short-elliptic, 2.4-5 x 
2-3.5 fx. 

The European form is reported on dead and dying branches and 
a form closely allied to it, probably identical, has been studied in 
New York as tlie cause of a raspberry cane-blight. This fungus 
and no other was present and typical disease followed inoculation. 
The organism was recovered in pure culture. Both new and old 
canes died within two months after inoculation. 



504 



THE FUNGI WHICH CAUSE PLANT DISEASE 



This is a conidial form of Leptosphseria coniothyrium. See 
p. 257.^^^ 

The same fungus was reported by Stevens & HalP^ and was 
studied by O'Gara^^ and determined by inoculation and cross 
inoculating, using pure cultures, to be the cause of rose and apple 
canker and apple fruit rot. 

C. diplodiella (Speg.) Sacc^^"* 

Pycnidia minute, subcuticular, erumpent, brown, 100-150 ix; 
conidia ovoid to elliptic, 7-11 x 5.5 (x; conidiophores simple or 
branched, hyaline, filiform. 

This is the cause of a v/hite rot of grapes and has been reported 




Fio. 349. — C. diplodiella, section through 
pycnidium. After Scribner. 



by Viali & Ravez as belonging to the ascigerous genus Carrinia.^ 
See p. 263. 

Though probably of American origin it was first recognized 
in Italy in 1878. In 1887 it caused alarm in France and it was 
first noted in America in the same year. The mycelium is abundant 
in the affected pulp and sometimes upon the seeds. Peduncles 
are often killed. The pycnidia are subcuticular, first pink, then 
white, later brown. 

C. scabrum McA. is the cause of black scurf of citrous fruit 
in Australia. 

C. coffeae Zimm. is on coffee in Java. 

C. vagabundum Sacc. causes premature fall of leaves of goose- 
berries. 

C. japonicum Miy., C. brevisporum Miy. and C. anomale 
Miy. are found on rice in Japan.''' 



THE FUNGI WHICH CAUSE PLANT DISEASE 505 

C. wernsdorffiae Kock occurs on roses. 
C. hellebori C. & M. is found on hellebore. 

Sphserioidaceae— Hyalodidymae (p. 480) 
Conidia hyaline, 1-septate, ovoid, ellipsoid or oblong. 

Key to Genera of Sphaerioidaceae— Hyalodidymae 

Pycnidia separate 
Pycnidia not beaked 
Pycnidia in discolored areas, maculicole 
Pycnidia immersed, then erumpent, 
perforate 

Conidia muticate 1- Ascochyta, p. 506. 

Conidia with setse at the apex. ... 2. Robillarda. 

Pycnidia superficial, astomous 3. Pucciniospora. 

Pycnidia not maculicole 

Pycnidia hairy 4. Didymochaeta. 

Pycnidia smooth 

Conidia with an appendage at each 
end 
Conidia with 1 or more bristles . 5. Darluca. 
Conidia with cap-like append- 
ages 6. Tiarospora. 

Conidia muticate 

Conidiophores 1-spored 

Pycnidia without subicle 7. Diplodina, p. 509. 

Pycnidia on a cobwebby subi- 
cle, phyllogenous S. Actinonema, p. 508 

Conidiophores several to many- 

gpored 9. Cystotricha. 

Pycnidia beaked 10- Rhynchophoma. 

Pycnidia in a stroma 
Stroma effuse 

Stroma consisting of two distinct 

layers H- Thoracella. 

Stroma of a single layer 12. Placosphaerella. 

Stroma verruciform 

Stroma superficial bi Patzschkeella. 

Stroma erumpent l-l- Cytodiplospora. 



506 THE FUNGI WHICH CAUSE PLANT DISEASE 

Ascochyta Libert (p. 505) 

Usually producing definite spots; pycnidia globose-lenticular, 
ostiolate; conidia ovate. 

About two hundred fifty species. 

A. pisi Lib.2i' ^i- 92=Mycosph8erella pinodes."*^^ See p. 250. 

Spots variable in size, roundish, yellowish with brown margin; 

pycnidia centrally located, black, of angular cells, 5-7 ijl; ostiole 

rounded, surface reddish brown; conidia 

slightly constricted at the septum, oblong, 

12-16 X 4-6 ju; exuded spore-mass brown. 

On peas, beans, vetch, Cercis, etc. The 
pycnidia are visible on the dead areas of the 
stems, leaves, pods or seeds. The mycelium 
hibernates in affected seeds, reduces their 
germinating power and carries the fungus 
over to the succeeding crop. 
Fig. 350.— a. citri, ^' boltshauseri Sacc. on bean in Swit- 
zerland ^^ is closely related to the last 
species. 

A. armoraciae Fcl. is on horse radish, causing leaf spots; 
A. ellisii Thiim. on grape; 

A. brassicae Thiim. on cabbage, forming large dull patches; 
often quite injurious. 
A. rhei E. & E. 

Spores finally constricted and 1-septate, 7-12 x 3.5-4 /x, hyaline. 
On rhubarb. 
A. viciae Lib. 

Epiphyllous; spots roundish, reddish, margin elevated, orange 
red; pycnidia minute, clustered, black, 90-100 n; conidia 
oblong-ovate, obtuse, slightly constricted, 12-15 x 4-5 n; exuded 
mass white. On Vicia. 
A. nicotianae Pass.^^ 

Spots between the veins, irregularly scattered, brown; conidia 
oblong ovate, constricted at the septum. On tobacco. 
A. parasitica Faut. 

Spots whitish; epiphyllous; pycnidia small, black. Conidia el- 
liptic, 3-4 X 6-10 n. 




THE FUNGI WHICH CAUSE PLANT DISEASE 507 

This is found associated with rust sori on malvaceous hosts. ^^' ^^ 

A. polemonii Br. & Cav. occurs on Polcmonium. 

A. piniperda Lin. is parasitic on fir leaves. 

A. aquilegiae Iloum. spots columbine leaves. 

A. beticola P. & D. is on beet leaves; 

A. orobi Sacc. on sainfoin; and A. oryzae Catt. on rice in Italy. 

A. lactucae Rost. is on lettuce; 

A. aesculi Bub. & Kab. on ^^culus in Europe; 

A. pallida Bub. & Kab. on Acer in Europe; 

A. pruni Bul3. & Kab. on the cherry in Europe; 

A. populicola Bub. & Kab. on the Silver Poplar in Europe; 

A. dianthi Berk, on Dianthus and other pinks; 

A. violae Sacc. causing spots on violet leaves; 

A. digitalis Fcl. on digitalis; 

A. iridis Oud. on Iris. 

A. juglandis Bolt, causes spots on leaves of Juglans;^^ 

A. aspidistras Mas. on Aspidistra. 

A. fragariae Sacc. 

Perithecia partly immersed, black, 100-125 n; conidia fusiform 
to cylindric, constricted, 14-27 x 4-5.5 /jl. 

This was reported by Dudley ^"^ as occurring in injurious form 
near Rochester, N. Y., causing spots, at first red, later brown, 
on strawberry leaves. 

A. primulae Wail.^^ 

Epiphyllous; pycnidia on discolored spots, scattered, depressed 
globose, 100-110 /x, pale brown, papillate ostiolate; conidia cy- 
lindric, obtuse, 5-6 x 2-2.5 fx. On Primula. 

A. chrysanthemi Stev.°^ 

Pycnidia few, immersed, early erumpent, single or scattered, 
hemispheric, amber-colored, 100-200 n; ostiole central, small, 
often raised bj^ a neck, dark-bordered; conidia oblong, straight 
or irregular, 3-6.2 x 10-20 n, apically obtuse, septum often ob- 
scure, sometimes more than one; not constricted till germination. 

It causes blighting of ray flowers of chrysanthemums. 

A. medicaginis Bres. 

Spots small, angular, pale, clustered; pycnidia sublenticular, 
apiculate, pale, becoming black, 200 x 160 n, context parenchy- 
matous; conidia oblong, obtuse, scarcely constricted, 10-12 x 4- 



508 



THE FUNGI WHICH CAUSE PLANT DISEASE 



4.5 IX. According to Stewart, French & Wilson, spots are caused 
on alfalfa.^^ The American form is distinct from the European 
and has been described under the name A. imperfecta Pk.'^^^ 

A. lycopersici Brum. 

Spots red or brown, large, rounded or irregular; pycnidia sparse, 
minute, black; conidia oblong, constructed, 8-10 x 2.5 ^i. 

Spots are produced on leaves and fruits of egg plant. 

A. caulicola Lau. causes injury to Melilotus alba.^°^ 

A. cookei Mas. is reported on Sweet William. 

A. corticola McA. is the cause of lemon l^ark-blotch in Australia, 
killing the trees. ^°^ 

A. graminicola Sacc. occurs on grasses and grains; 





Fig. 351. — Actinonema rosae. 8, branching strand of superficial 
mycelium; 4, spores. After Southworth. 

A. manihotes Hen. on cassava in Africa. 
A. tremulae Sacc. occurs on aspen; 
A. melutispora B. & Br. on ash. 



Actinonema Fries (p. 505) 

Pycnidia very small, not ostiolate, with a radiating mycelial 
growth on the surface of the host; conidia elongate, on short 
conidiophores. 

A genus of about fifteen species, chiefly leaf parasites, 

A. rosae (Lib.) Fr.^^' ^^^ 

Spots rounded or irregular, black or purple, epiphyllous, often 



THE FUNGI WHICH CAUSE PLANT DISEASE 



509 



confluent, marginally fimbriate, the radiating fibers arachnoid, 
white, distinctly branched; pycnidia tuberculariform, scattered 
or confluent, black; conidia oblong, constricted, 18-20 x 5. n; 
conidiophores short. 

This fungus was first described in 1826. It is common on rose 
leaves. The mycelium is in part subcuticular, in part deeper. 
The subcuticular part is visible through the cuticle, consisting 
of radiate strands each composed of several parallel hypha3. From 
this mycelium branches penetrate deep into the leaf. The dark 
color of the leaf spots is due to discoloration of the contents of the 
diseased cells; the mycelium itself having little or no color. 

A. tiliae All. causes defoliation of Tilia. 

A. fagicola All. occurs on beech leaves; 

A. fraxani All. on ash. 



Diplodina Westendorp (p. 505) 

Pycnidia immersed or erumpent, globose; ostiole papillate, 
black, small; spores elongate. 
It differs from Diplodia only 
in the hyaline spores. 

About eighty species chiefly 
saprophytes. 

D. citrullina (C. O. Sm.) 
Gres. on cucurbs=Mycosph8e- 
rella cirullina. See p. 246. 

D. castaneae P. & D. in- 
jures chestnut leaves, and 

causes cankers on the shoots in France, resulting in serious 
loss.^°2 

D. parasitica (Hart.) Prill, occurs on the basal leaves of young 
shoots of spruce causing defoliation. 

D. salicina C. & M. causes tips of willows to die. 
D. corticola A. & S. is found on cacao in Africa. 




Fig. 352. — D. castanese, pycnidium and 
spores. After Delacroix. 



Sphaerioidaceae-Phaeodidymae (p. 480) 
Conidia dark, 1-septate, ovoid to oblong. 



510 THE FUNGI WHICH CAUSE PLANT DISEASE 

Key to Sphaerioidaceae-Phaeodidymse 

Pycnidia separate 
Pycnidia beaked 

Pycnidia hairy 1. Rhynchodiplodia, p. 510. 

Pycnidia smooth 2. Pellioniella. 

Pycnidia not beaked 

Pycnidia hairy 3. Chaetodiplodia, p. 510. 

Pycnidia smooth 

Conidia with a mucous layer, 

very large 4. Macrodiplodia. 

Conidia without a mucous laj'cr 
Pycnidia erumpent, conidia 
muticate 
Conidia less than 15 m long. 5. Microdiplodia, p. 510. 
Conidia 15 ju or more long. 6. Diplodia, p. 511. 
Pycnidia superficial, lignicole. 7. Diplodiella, p. 512. 
Pycnidia cespitose or in a stroma 

Pycnidia cespitose 8. Botryodiplodia, p. 513. 

Pycnidia in a stroma 

Pycnidia and subicle enclosed in a 

hemispheric stroma 9. Lasiodiplodia, p. 513. 

Pycnidia without subicle, in a 

globose stroma 10. Diplodiopsis. 

Rhynchodiplodia Briosi & Farneti 

Pycnidia rostrate, pilose ; conidia oblong. 

A single species, R. citri B. & F., causes disease of the lemon. 

Chaetodiplodia Karsten 

Pycnidia erumpent, globose, ostiolate, black, membrano- 
carbonous, hairy or bristly; conidia elongate. 

A genus of about ten species, chiefly saprophytes. 
C. vanillae Zimm. is on vanilla. 

Microdiplodia Allescher 

Pycnidia subcuticular, erumpent, membranous to subcarbon- 
ous, globose or depressed, minutely ostiolate; conidia ovoid to 
oblong, small, (under 15 n.) 



THE FUNGI WHICH CAUSE PLANT DISEASE 



511 



More than twenty-five species, chiefly saprophytes. 
M. anthurii Trinch. occurs on Anthurium. 



Diplodia Fries (p. 510) 

Pj^cnidia immersed, erumpent, carbonoiis, black, usually 
ostiolate-papillate; conidia ellipsoid or ovate; conidiophores 
needle-shaped, simple, hyaline. 

Over four hundred fifty species, many of them saprophytes. 

D. zeae (Schw.) Lev.^"^"^'^^ 

On ears and stalks of corn, pycnidia borne on the husks, cobs, 
stalks and rarely the grains, gregarious, small, lenticular to flask- 
shaped or irregular, papillate; conidia elliptic, straight or curved, 
constricted or not, 25-30 x 6 ju. 

It occurs as the cause of a very serious drj^ rot of ear corn. 

The actual growing mycelium is hyaline and much branched. 

Pycnidia in the cob are principally on the scales which surround 
the inner ends of the kernels and are set in a dense mass of white 
mycelium. On dead stalks 
the pycnidia form below 
the rind, particularly at 
the nodes, breaking 
through during the follow- 
ing summer, and extruding 
the spores in cirri. 

The fungus was studied 
extensively by Burrill & 
Barrett ^°^ and inoculations 
were made using pure cul- 
tures. Spores placed under 
the husk or in the silk, or sprayed upon plants in suspensions, re- 
sulted in disease. 

Smith and Hedges ^°^ report that infection is often by way of the 
root system, the mycelium reaching the grains through the stem 
and from the cob. 

D. macrospora Ea. 

Pycnidia scattered, large, erumpent, carbonous; conidia elon- 
gate, irregularly clavate, curved or constricted, 70-80 x 6-8 //. 




Fig. 353.- 
nel 



-Pycnidia of Diplodia, from corn ker- 
After Burrill and Barrett. 



512 THE FUNGI WHICH CAUSE PLANT DISEASE 

This is responsible for a corn mold similar to that caused by 
the last species. ^°^ 

Other parasitic species are : 

D. oryzae Miy. on rice; 

D. cerasorum Fcl. on cherries; 

D. aurantii Catt. on oranges; 

D. mori West, on Morus; 

D. gongrogena Temme on Populus in Germany; 

D. sapinea (Fr.) Fcl. on conifers; 

D. pinea Kick, on pine leaves in Europe; 

D. coffeicola Zimm. on coffee; 

D. perseana Del. on the avocado. 

D. opuntiae Sacc. is sometimes a serious pest of the cactus. 

D. citricola McA. occurs in Australia on lemon twigs, stems 
and green fruit. ^°^ 

D. destruens McA. is on orange and lemon leaves in Australia; ^°^ 

D. heteroclita D. & M. on Citrus in Algiers. ^"^ 

D. cacaoicola Hen. does much injury to cacao and sugar 
cane ''*^ in the West Indies. 

D. natalensis Ev. causes a serious black rot of citrus fruits in the 
Transvaal; ^°^ 

Pycnidia scattered, covered, later erumpent, black; papillate 
150-180 n; spores elliptical, 1-septate, not constricted, dark, 24 
X 15 fx, exospore with striated bands. 

A Diplodia which cannot be distinguished from this was studied 
l)y Fawcett and Burger and is reported as the cause of gum- 
mosis of peach and orange in Florida. "^^ Pure culture inoculations 
and cross inoculation showed the same fungus able to cause the 
disease on both hosts. 

D. rapax Mas. is the cause of a stem disease of Para rubber. 

D. epicocos Cke. grows on the coconut and an undetermined 
species attacks ripe pineapples. 

Diplodiella Karsten (p. 510) 

Pycnidia superficial, globose, ostiolate papillate, black, smooth, 
rather carbonous; conidia elliptic. 

About twenty-five species, chiefly saprophytes on wood. 
D. oryzae Miy. is found on rice. 



THE FUNGI WHICH CAUSE PLANT DISEASE 513 



Botryodiplodia Saccardo (p. 510) 

Pycnidia botryose-confluent, erumpent, stromatic, membrano- 
carbonous, black, usually ostiolate-papillate ; conidia elongate or 
ovate. 

Over thirty species, chiefly saprophj^es. 

An unnamed species of this genus is given by Butler as the 
probable cause of a coconut palm disease in India. ^°^ 

Lasiodiplodia Ellis & Everhart (p. 510) 

Pycnidia collected on a stroma, 2 0^ ^ ^ 
covered with a brown mycelium, paraph- ir_,', 

yses among the conidiophores. Other- z;^^" -^ 

wise as in Diplodia. 

Two species, both parasites. 

L. tubericola E. & E.^i" 

Pycnidia globose, 250-305 n; stro- 
matic mass about 1 mm. in diameter; co- ^ 
nidia elliptic, 18-22 x 11-14 ju, not con- ^\- 
stricted; conidiophores short; paraph- ^-r 
yses 45-55 n long, overtopping the '-'■^^=^^ 

conidia. ■^'"^- 354.-^Lasiodiplodia tu- 

bericola. Perithecium, pa- 
It was found on sweet potatoes from raphyses and spores. After 

Java which were brought to the 
Louisiana Experiment Station in 1894. 
L. theobromae (Pat.) G. & M. is a wound parasite of Hevea. 

Sphaerioidacese-Hyalophragmiae (p. 480) 
Conidia hyaline, 2 to many-septate, oblong to fusoid. 

Key to Genera of Sphaerioidaceae-Hyalophragmiae 

Pycnidia more or less globose 
Subicle none 

Conidia appendaged at apex 

Setse 1 1 . Kellermania. 

Setae 3 2. Bartalinia. 





514 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Conidia muticate 3. Stagonospora, p. 514. 

Subicle present, dark, phyllogenous 4. Asterostomidium. 

Pycnidia elongate to cylindric 5. Mastomyces, p. 514. 

Stagonospora Saccardo 

Pyenidia superficial or erumpent, 
globose, ostiolate-papillate, black, 
membranous or subcarbonous ; co- 
nidia elongate, 3 or more-celled. 

Over one hundred species, chiefly 
saprophytes; differing from Hen- 
dersonia only in the hyaline conidia. 

S. carpathica Batumi. 

Spots circular, 1-3 mm., light 
browTi with a narrow darker border; 
pycnidia 120-180 ju; conidia escaping 
in a gelatinous mass, straight or 
M, 2 to 5-celled, frequently slightly 




Fig. 355. — Stagonospora. C, pyc- 
nidium in section. D, spores 
After Corda. 



slightly curved, 14-28 x 4 
constricted.^^ It causes leaf spots on alfalfa. 
S. iridis Mass. occurs on iris. 

Mastomyces Mont. 

Pycnidia gregarious, separate, erumpent, elongate, papillate- 
ostiolate; conidia fusiform, 3-septate. 

There are two species, one of which, M. friesii Mont., is 
probably the conidial form of Scleroderris ribesia, see p. 155, the 
cause of a relatively unimportant currant disease of Europe. 

Sphserioidaceae-Phaeophragmiae (p. 480) 
Conidia hyaline, 2 to several-septate, oblong to fusoid. 

Key to Genera of Sphaerioidaceae-Phaeophragmiae 

Pycnidia separate 
Pycnidia not beaked 

Conidia free from each other 
Conidia muticate 

Pycnidia papillate or subastomous 

Pycnidia with flattened base 1. Macrobatis. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



515 



Pycnidia globose, without flat- 
tened base but on a stellate 

superficial subicle 2. Couturea. 

Pycnidia without a subicle, 
erumpent 

Pycnidia hairy 3. Wojnowicia. 

Pycnidia smooth 4. Hendersonia, p. 515. 

Pycnidia opening widely, with an 
operculum 
Pycnidia superficial, dark, hairy 5. Angiopoma. 
Pycnidia immersed, pale, smooth 6. Lichenopsis. 
Conidia appendaged 

Conidia 1-ciliate at each end 7. Cryptostictis, p. 516. 

Conidia 1-ciliate at base 8. Urohendersonia. 

Conidia with a round or cup-like 

appendage at each end 9. Santiella. 

Conidia united in groups 

Conidia united into a fascicle 10. Eriosporina. 

Conidia stellately united 11. Prosthemium. 

Pycnidia beaked 12. Pseudographium. 

Pycnidia in a stroma 13. Hendersonula, p. 516. 



Hendersonia Berkley 

Pycnidia immersed, erumpent or not, 
globose with a papillate ostiole or depressed, 
membranous or subcarbonous; conidia elon- 
gate or fusoid, 2 to many-septate. 

Some two hundred fifty species, chiefly 
saprophytic, although there are several para- 
sitic species. 

H. mail Thiim. 

Epiphyllous; pycnidia disciform, large, 
scattered, black, on brownish, orbicular, 
violet-margined spots; conidia clavate, apex 
rounded, base somewhat acute, not constricted, 12-14 x 4-5 m- 

On leaves of apple in Europe and America. 

H. piricola Sacc. is on pear; H. cydonae C. & E. on quince; 

H. acicola INI. & T. causes a pine leaf disease.^^^ 

H. cofifeae Del. is on coffee; 




Fig. 356. — Hender- 
son i a, hymenium 
and spores. After 
Starback. 




516 THE FUNGI WHICH CAUSE PLANT DISEASE 

H. oryzae Miy. on rice; 

H. notha Sacc. & Br, on Juniperus leaves; 

H. togniniana Poll, on Cycas. 

H. foliicola (Berk.) Fcl.^^^ 

Pycnidia epiphyllous, broA\Tiish-black, subglobose, subelliptic 
or irregular; conidia elliptic to clavate, obtuse, 3 to 5-septate; conid- 
iophores filiform, radiating. On Juniperus and Pine. 

Cryptostictis Fuckel (p. 515) 

Pycnidia erumpent, globose or depressed, 
ostiolate; conidia elongate, 2 or more septate, 
subapically appendiculate with a long hyaline 
bristle. It differs from Hendersonia chiefly in 
spore characters. 

A small genus of eleven species, chiefly sapro- 

FiG. .357.— Cryptos- phytes. 

tictis, spores. Af- Q^ cvnosbati (Fcl.) Sacc. and 

ter Starback. ^ , .-^ \ r, 

C. caudata (Preu.) Sacc. occur on the rose, 
the former on the fruit and branches forming wounds. 

Hendersonula Speg. (p. 515) 

Stroma black, irregular; ostioles punctiform; spores ellipsoid, 
several-celled, colored. In part =Plowrightia. 

A form on the plum=Plowrightia morbosa. See p. 218. 

Sphaerioidaceae-Phaeodictyse (p. 480) 

Conidia dark, muriform, oblong to ovoid, rarely radiate or 
cruciate. 

Key to Genera of Sphaerioidaceae-Phaeodictyae 

Pycnidia separate 

Conidia not reticulate 

Pycnidia on bark, erumpent 1. Camarosporium, p. 517. 

Pycnidia on wood, superficial 2. Cytosporium. 

Conidia reticulate 3. Endobotrya. 

Pycnidia merely locules in a stroma 4. Dichomera. 




THE FUNGI WHICH CAUSE PLANT DISEASE 517 

Camarosporium Schulzer von Miiggenburg (p. 516) 

Pycnidia immersed, erumpent, separate, 
globose, ostiolate, papillate, carbonous or 
submembranous; conidia ovate to fusiform, ^ 

muriform, with 2 to many cross walls. 

Over one hundred twenty species, chiefly Pf^ f^-L 
saprophytes. V^ i^"^ 

C. fissum (Pers.) Star, causes injury to ^' ^'^ 

roses. ' ^ 

C. viticola (Cke. & H.) Sacc. is reported on 

grape; Fig. 358. — Camaro- 

C. CI T\T sporium, spores. 

. men Sacc. on MorUS. After Starback. 

Sphaerioidaceae-Scolecosporae (p. 480) 

Conidia hyaline or light colored, elongate-fusoid, rod-shaped 
or filiform, continuous or septate. 

Key to Genera of Sphaerioidaceae-Scolecosporse 

Pycnidia separate 

Pycnidia membranous or carbonous 
Pycnidia superficial 
Pycnidia hairy 

Conidia single on the conidiophores 1. TrichocoIIonema. 
Conidia ternate on the conidio- 
phores 2. Gamospora. 

Pycnidia smooth 

Pycnidia beaked 3. Cornularia. 

Pycnidia not beaked 

Conidia usually expelled in a ball 4. CoUonema. 
Conidia not expelled in a ball. . 5. Septorella. 
ycnidia immersed or erumpent 

Pycnidia hairy, maculicole 6. Trichoseptoria, p. 518. 

Pycnidia smooth 

Pycnidia beaked 7. Sphaerographium. 

Pycnidia not beaked 

Pycnidia maculicole, mainly 
phyllogenous 

Conidia hyaline 8. Septoria, p. 518. 

Conidia colored 9. Phaeoseptoria, p. 525. 



518 THE FUNGI WHICH CAUSE PLANT DISEASE 

Pycnidia not maculicole 

Pycnidia complete at top, 

usually papillate 10. Rhabdospora, p. 525. 

Pycnidia more or less incom- 
plete at top 
Pycnidia gaping, showing a 

gelatinous spore mass. 11. Gelatinosporium. 
Pycnidia not exposing a ge- 
latinous mass 

Pycnidia foliicole 12. Phleospora, p. 525. 

Pycnidia rami-caulicole. . 13. Phlyctaena. 
Pycnidia suberose, incomplete, often pale 

Pycnidia cespitose 14. Micropera. 

Pycnidia merely gregarious 15. Micula. 

Pycnidia in a stroma 
Conidia 4 to 6-fasciculate on a conidio- 

phore 16. Eriospora. 

Conidia separate 

Conidia setose-penicillate 17. Dilophospora, p. 525. 

Conidia muticate 

Stroma superficial, setose 18. Septodothideopsis. 

Stroma erumpent or immersed 
Pycnidia distinct in the stroma, 

conidia hyaline 19. Cytosporina, p. 526. 

Pycnidia as locules in the stroma, 

conidia colored 20. Septosporiella. 

Trichoseptoria Cavara (p. 517) 

Pycnidia separate, erumpent, on spots, membranous, hairy; 
conidia needle-shaped, septate. 

A single species. T. alpei Cav.^^^ is reported by Cavara as 
injurious to lemon fruits in Italy. 

Septoria Fries (p. 517) 

Pycnidia immersed, usually on leaf spots, globose lenticular, 
ostiolate, membranous, black; conidia narrowly elongate to fili- 
form, multiseptate, hyaline, conidiophores very short. 

Over nine hundred species, all parasitic, several of them of 
considerable economic importance but most of them occurring on 
non-economic hosts. 



THE FUNGI WHICH CAUSE PLANT DISEASE 519 

In part=Mycosph3erella, Leptosphcpria. 

The genus is a very large one similar to Phoma and Phyllosticta 
except in its spore form and in the ostiole which is frequently 
very large. Septoria and Phleospora are distinguished only by 
the lesser development of the walls of the latter and many species 
which in early stages pass as Phleospora would in older stages be 
classed as Septoria. 

Septoria and Rhabdospora are distinguished only by the part 
of the host affected, stem or leaf, and many forms in these two 
genera are undoubtedly identical. 

S. pisi West, is on peas. 

S. piricola Desm. on pear and apple = My cosphserella sentina. 
See p. 246. 

S. populi Desm. on Populus=Mycosph8erella populi. See p. 250. 

S. phlogis Sacc. & Speg. on Phlox =Leptosph2eria phlogis. See 
p. 258. 

S. ribis Desm.^^^ 

Hypophyllous; spots small, irregular, bounded by the leaf veins, 
brownish-purple ; pycnidia in- 
nate, minute, convex, brownish- 
black; cirri in mass reddish; co- 
nidia elongate, linear, curved, 
50 fjL long. 

On gooseljerry and currant, 
causing leaf spots and defolia- 
tion. 

S. aciculosa E. & E. Fig. 359.— S. nbis, a pyemdium and 

Pycnidia innate to superficial, ^p"^*^^- ^^t^'" ^^""gyear. 

grouped, minute, amphigenous; conidia needle-shaped, continuous, 
15-20 x 0.75 ^l. 

It is found on the strawberry. 

S. fragariae Desm. 

Epiphyllous; spots suborbicular, brown, wdth reddish-brown 
margin; pycnidia minute, innate, prominent, brownish; cirri white; 
conidia cylindric, obtuse, 3-septate. 

Perhaps =Mycosph8erella fragariae. See p. 244. 

On strawberry, cultivated and wild, forming circular leaf 
spots. 




520 THE FUNGI WHICH CAUSE PLANT DISEASE 

S. cerasina Pk.^^^ 

Spots scattered or confluent, minute, subangular, b^o^\^l or 
reddish-brown; pycnidia pale, collapsing; conidia filiform, straight 
or curved, 50-75 jj. long. On cherry. 

S. pruni E.^^^ 

Spots dark brown, dry, subrotund, soon breaking out, 1-3 mm. ; 
pycnidia brown, immersed, 60 m; conidia linear, obtuse, 4 to 
6-septate, 30-50 x 2 /x. On plum. 

S. limonum Pass, and S. sicula Penz, occur on citrus; 

S. glaucescens Trab. on the mandarin; 

S. loefgreni N. on oranges in Brazil; 

S. ampelina B. & C. on the grape. 

S. longispora Sh. (not Miy.) is found on the cranberry.^^^ 

S. graminum Desm.^^^"^^^ 

Spots slightly elongate, pale, fuscous-margined, limited by the 
leaf veins; pycnidia seriate or scattered, brownish; conidia very 
slender, straight or curved, non-septate, but multiguttulate, 
55-75 X 1-1.3 /x. 

This is a frequent saprophyte or weak parasite on wheat, oats 
and numerous wild grasses. Under some conditions it becomes 
an injurious parasite, especially upon winter wheat. 

S. tritici Desm. is closely Hke S. graminum. ^^^ 

It is associated with Leptospheeria tritici on wheat. See 
p. 258. 

S. glumarum Pass, is also found on wheat. 

S. nodorum Berk, occurs, particularly at the nodes, on the same 
host. 

S. secalina Jancz. is on wheat and rye leaf sheaths; 

S. avenae Frank, on leaves of oat. 

S. longispora Miy. (not Shear) and S. curvula Miy. are on 
rice. 

S. betaB West. 

Spots pale brown, white in the center, brownish-margined; 
pycnidia epiphyllous, minute, black, prominent; conidia cylindric, 
straight or curved, white in mass. 

It was noted by Humphrey ^^^ causing a beet leaf spot. 

S. citruUi E. & E. 

Spots small, round, white, scattered; pycnidia mostly solitary, 



THE FUNGI WHICH CAUSE PLAxNT DISEASE 



521 



one in the center of each spot, but slightly prominent; conidia 
cylindric or clavate-cylindric, 10-25 x 1.5-2 jx. 

On watermelon leaves. 

S. cucurbitacearum Sacc. is also on cucurbits. ^^ 

S. cannabina Pk. is on hemp producing leaf spots. 

S. nicotianae Pat. is reported from France as the cause of tobacco 
leaf spotting. ^^"^ 

S. dolichi B. & C. 

Spots white, with a broad, light brown margin; conidia straight, 
subfusiform, 3-septate, 40 /x. On cowpeas.^^^ 

S. medicaginis Rob. & Desm. is on alfalfa. 

Spots whitish, angulate-subcircular, confluent; pycnidia len- 
ticular, 70-90 m; conidia slender, vermiform, tortuous, 60-70 x 1 /i, 
septate. 

S. petroselini Desm. 

Spots brown, in age white, amphigenous; pycnidia epiphyllous, 
minute, olivaceous, promi- 
nent; conidia filiform, straight 
or curved, 35-40 x 1-2 ju- On 
parsley. 

S. petroselini apii Br. & 

CaV.25' 122-126 

This common and very de- 
structive fungus on celery 
leaves was first described in 
Italy by Cavara and in 
America it was early noted 
by Chester ^^s and Halsted.^'^ 
The pycnidia are abundant in 
the leaf spots and in the case 
of stored celery they are 
found scattered over the blanched petioles 
a host variety. 

S. lycopersici Speg.^^' ^"^' ^^^ 

Spots large, often confluent and covering the entire leaf, sordid 
cinereous, subindeterminate ; pycnidia scattered, hypophyllous, 
lenticular-hemispheric, prominent, membranous; conidia elongate, 
cylindric, 70-110 x 3.3 ^i, pluriseptate. 




Fig. 360. — S. petroselini apii. Pycnidiuni 
showing spores oozing through the ostiole. 
After Jensen. 



Essentially it is only 




522 THE FUNGI WHICH CAUSE PLANT DISEASE 

The cause of leaf spots of tomato. It was noted in New Jersey 
about 1893 ^^'^ and in Ohio in 1896.^-^ It is one of the serious 
tomato pests. 

S. lactucae Pass.''^" 

Spots irregular, brownish, angulate, sometimes destroying the 
entire leaf, pycnidia minute, punctiform, scattered, 90 n in 
diameter, conidia filiform, straight or curved, 25- 
30 X 1.7-2 n. 
On lettuce. 

S. consimilis E. & M.^^ 

Distinguishable from the preceding by the more 
indefinite spots, slightly larger pycnidia (90-100 n) 
and longer conidia (30-45 x 2-2.5 n). It causes 
brown spots on lettuce leaves. 
Fig. ^.-Spores S. armoraciae Sacc.^^ 
of s. lycopcrsici. Spots irregular, ochraceous; pycnidia puncti- 
form, grouped in the center of the spot, 60 n; 
conidia filiform, curved, 15-20 x 2-2.5 fx, 1 to 3-septate. On 
horseradish causing leaf spot. 

S. antirrhini Desm. attacks the snapdragon severely. ^-^ 
S. rosae Desm. is on rose; 
S. hydrangese Bizz. on cultivated hydrangea; 
S. iridis C. Mass. on Iris. 
S. cyclaminis Dur. & M. on cyclamen. 
S. sedi West. 

Epiphyllous; spots circular, gray to gray-brown; pycnidia mi- 
nute, numerous, brown, scattered, erumpent; conidia cyHndric, 
straight or curved, 5-guttulate; cirri white. On cultivated Sedum. 
S. hederae West, is on Hedera; 

S. rostrupii Sacc. & Syd. and S. varians Jaff. on chrysanthe- 
mum; as is also: 

S. chrysanthemella Cav. ' Spots ochraceous, dark mar- 
gined; pycnidia epiphyllous, punctiform; conidia 40-50 x 2.5-2 n, 
obscurely septate. 

It causes damping off of chrysanthemum cuttings and spotting 
of the leaves. ^^^ 
S. dianthi Desm.^^ 
Spots yellowish, oblong, roundish or irregular; pycnidia globose, 



THE FUNGI WHICH CAUSE PLANT DISEASE 523 

depressed, brownish-black; cirri white; conidia elongate, cylindric, 
curved, obtuse, 30-45 x 4 /x. 

It is the cause of a common and injurious leaf spot of the car- 
nation. The pycnidia are visible as dark specks on the blanched 
background of the spot. 

S. azaleae Vogl. 

Spots reddish-yellow; pycnidia amphigenous, immersed, globose 
to depressed, black; conidia oblong cylindric, filiform, straight or 
curved, 1 to 3 or more septate, constricted slightly at the septa, 
12-18 X 1.5-2.5 At; conidiophores cylindric, short, 3-5 m long. 

On Azalea. 

S. divaricatae E. & E. 

Spots whitish, amphigenous, confluent, purple-bordered; pyc- 
nidia numerous, epiphyllous, lenticular, 100-120 n, dull black; 
conidia 18-30 x 0.75-1 /x, nearly straight, non-septate, finely 
guttulate. 

It frequently injures cultivated phlox. ^* 

S. narcissi Cass, is on Narcissus. 

S. exotica Speg. is on Veronicas in cultivation. 

S. fairmanii E. & E. 

Spots amphigenous, scattered, subangular, 3-4 mm. dark 
brown, limited by the veins, with a narrow dark margin; pycnidia 
epiphyllous, scattered, rather numerous, black, subprominent, 
100-112 ijl; conidia filiform, slightly curved, guttulate, 30-45 x 
1.5-2 M. 

It parasitizes hollyhock leaves. ^^ 

S. parasitica Fau. 

Spots amphigenous, white; pycnidia punctiform, innate; conidia 
cylindric, 30-40 x 3.5-4 n. 

The conidia are broader than in the preceding species and the 
gross appearance is quite different. It is found associated with 
rust sori on hollyhock. ^^ 

S. helianthi E. & K. 

Spots brown, definite, 2.5-7.5 mm. with a yellowish elevated 
margin; pycnidia epiphyllous, immersed, brown, collapsing, 105 fx; 
conidia linear-filiform, 3 to 5-septate, 30-70 x 2-3 /x-^^" 

On sunflower leaves. 

S. majalis Aderh. causes a leaf spot of lily-of-the-valley; 



524 THE FUNGI WHICH CAUSE PLANT DISEASE 

S. oleandrina Sacc. In leaf spots of oleander. 

S. veronicae Desm. 

Spots amphigenous, small, subrotund, brownish or grayish, 
becoming white, border umbrinous; pycnidia epiphyllous, glo- 
bose, prominent, pale brownish-black; conidia elongate, slender, 
straight or flexuose. 

It is parasitic on cultivated Veronicas.^* 

S. caraganae Hen. is on Caragana. 

S. ochroleuca B. & C. 

Spots scattered, suljorbicular, pale, brown margined; pycnidia 
central, minute, scattered, hypophyllous, pale, collapsing; conidia 
fusoid-filiform, curved, continuous or 1-septate, 25 ^ long. 

In leaf spots on chestnut. 

S. castanicola Desm. and S. castanea Lev. are on chestnut; 
S. nigro-maculans Thiim. on walnuts and horse-chestnut; 

S. aesculi Lib. and S. hippocastani B. & Br. on horse- 
chestnut. 
. S. pseudoplatini R. & D. occurs on sycamore and maple; 

S. fraxani Desm. on ash; 

S. cercidis Fr. on Cercis; 

S. tiliae West, on I'ilia; 

S. curvata (R. & B.) Sacc. on Robinia leaves. 

S. spadicea P. & C.^^^ causes a common twig blight of 
pine. 

Pycnidia not spot-forming, late, becoming slightly erumpent 
on inner surface of browning needles, scattered, membranous, 
fuscous-olivaceous, subimmersed, 190-225 m in diameter. Spores 
hyaline, cylindrical, slightly curved or flexuous, apex acute, 
1-septate, rarely constricted at septum, 3-4 x 30-45 ju- Conidio- 
phores short. 

S. ulmariae Oud. Pycnidia minute, immersed, spores cylindric, 
curved, hyaline, continuous, 5.0 x 2.5 /x. On Spirea. 

S. cornicola Desm. 

Spot orbicular, margin dark purple; pycnidia epiphyllous, few, 
black; spores cylindric, curved, 35-40 x 2-2.5 fx, obsolete 2 to 4- 
^septate, hyaline. On Cornus. 

S. parasitica Hart, is found on young spruce buds killing the 
lateral shoots. 



THE FUx\GI WHICH CAUSE PLANT DISEASE 525 



Phaeoseptoria Miyabe (p. 517) 

As in Septoria but with colored conidia. 
P. oryzae jMiy. is on rice in Japan. 

Rhabdospora Montaigne (p. 518) 

Pycnidia innate, erumpent, globose or depressed, brown or 
black; conidia as in Septoria. 

Similar to Septoria, but on stems. 

R. coffeicola Del. and R. coffeae Del. are on coffee; 

R. theobromaB A. & S. on cacao; 

R. oxycocci Sh. on cranberry. 

R. rubi E. Pycnidia black, subglobose, innate, erumpent, 
scattered, 100-195 /jl; conidia linear, curved, 3 to 4-septate, 40- 
45 X 3 Ai. On blackberry. 

Phleospora Wallroth (p. 518) 

Pycnidia innate, imperfectly developed, and chiefly formed of 
modified host tissue; conidia elongate-fusoid, thick, 2 to many- 
septate. About twenty-five species of leaf parasites. 

This genus closely approaches the Melanconiales in structure. 
Several forms have been shown to be allied to Mycosphserella, e. g., 
P. ulmi to M. ulmi. 

P. mori (Lev.) Sacc. on Morus=CyHndrosporium mori =My- 
cosphsella. 

P. moricola (Pass). Sacc. on Morus is a conidial form of 
Septoglceum mori. 

P. aceris Lib. is found on maple and sycamore leaves; 

P. oxycanthae Desm. on hawthorn leaves; 

P. caraganae Jacz. on Caragana.^^^ 

Dilophospora Desmazieres (p. 518) 

Pycnidia globose, ostiolate, usually stromatic ; conidia cylindric, 
unicellular, with hair-like appendages at each end. 
In part =Dilophia. 
D. graminis Desm. =Dilophia graminis. See p. 257. 



526 THE FUNGI WHICH CAUSE PLANT DISEASE 



Cytosporina Saccardo (p. 518) 

Stroma valsoid, cushion-formed or tubercular; pycnidia sunken, 
the ostiole erumpent; conidia filiform, curved, 1-celled. 

Twenty species of bark and wood inhabiting fungi. 

These are, in part at least, conidial forms of the Valsacese. 

C. ribis Miy.^^^ occurs on currant and gooseberry bushes in 
Holland attacking the cortex, later the wood, and killing the 
shoots. 

Nectrioidaceae (p. 479) 

Pycnidia fleshy or waxy, light colored, globose, rarely cup- 
shaped or hysterioid; stroma present or absent; conidia various, 
usually hyaline. 

This group contains some twenty-five genera none of which are 
serious plant pathogens. Some are conidial forms of the ascigerous 
fungi Aschersonia and Polystigma. 

Key to Subfamilies and Groups of Nectrioidaceae 

Pycnidia globose, ostiolate I. Zythieae. 

Conidia 1-celled 

Hyaline 1. Hyalosporae, p. 526. 

Dark colored 2. Phaeosporae. 

Conidia two-celled hyaline 3. Hyalodidymiae. 

Conidia 3 to several-celled, hyaline 

Elliptic to fusoid 4. Hyalophragmiae. 

Bacillar to filiform 5. Scolecosporae. 

Pycnidia cupulate or hysterioid II. OUuleae. 

Zy thie se-Hy alosporae 

Conidia hyaline, continuous, ovoid to elliptic. 

Key to Genera of Zythiaceae-Hyalosporse 

Pycnidia separate 
Pycnidia smooth 
Pycnidia beakless 
Conidia in chains 1 . Sirozy thia. 



THE FUNGI WHICH CAUSE PLANT DISEASE 527 

Conidia not in chains 

Pycnidia on creeping hyphsD 2. Eurotiopsis. 

Pycnidia without mycelium 
Conidia spiny or cihate 

Conidia spiny 3. Roumegueriella. 

Conidia with several cilia at 

apex 4. Ciliospora. 

Conidia smooth 

Pycnidia single-walled 
Pycnidia more or less papil- 
late 5. Zythia, p. 527. 

Pycnidia with crateriform 

ostiole 6. Libertiella. 

Pycnidia cup-shaped 7. Lemalis. 

Pycnidia with outer circum- 

scissile wall 8. Dichlaena. 

Pycnidia beaked 9. Sphaeronemella. 

Pycnidia hairy or spiny 

Pycnidia densely beset with conoid 

1-cellcd setse 10. Muricularia. 

Pycnidia with slender bristles or hairs 

Hairs fasciculate 11. Collacystis. 

Hairs separate 
Hairs everywhere but at the apex 12. Chaetozythia. 
Hairs only around the wide ostiole 13. Pseudozythia. 
Pycnidia cespitose or in a stroma 

Pycnidia cespitose, beaked; conidia in 

chains 14. Treleasiella. 

Pycnidia in a stroma 

Stroma more or less pulvinate 

Conidia fusoid 15. Aschersonia. 

Conidia globose 16. Munkia. 

Stroma fruticose, branched; conidia 

bacillar 17. Hypocreodendron. 

Zythia Fries 

Pycnidia erumpent or superficial, globose, with more or less 
evident papillate ostioles, white or bright colored; conidia ovate 
or elongate. 

Some twenty species. 



528 THE FUNGI WHICH CAUSE PLANT DISEASE 

Z. fragarise Lail). Is said to cause a strawberry disease. 

Leptostromataceae (p. 479) 

Pycnidia membranous or carbonous, black, more or less dis- 
tinctly dimidiate, scutiform, astomous, ostiolate or cleft, erumpent 
or superficial. Over two hundred species. 

Key to Sections of Leptostromataceae. 

Conidia l-celled 

Hyaline 1. Hyalosporae, p. 528. 

Colored 2. Phaeosporae, p. 531. 

Conidia 2-celled 

Hyaline 3. Hyalodydimae. 

■ Colored 4. Phaeodidymae. 

Conidia 3 to several-celled 

Hyaline 5. Hyalophragmiae, p. 531. 

Colored 6. Phaeopharagmiae. 

Conidia 1 to several-celled, filiform 7. Scolecosporae, p. 532. 

Leptostromataceae-Hyalosporae 

Conidia hyaline, l-celled, globose to ovoid. 

Key to Genera of Leptostromataceae-Hyalosporse 

Pycnidia separate 
Pycnidia astomous or variously perforate, 
but not cleft 
Conidiophores lacking 
Pycnidia on a subicle 

Subicle of fumaginous hyphse 1. Eriothyrium. 

Subicle of broad fibers 2. Trichopeltulum. 

Pycnidia without subicle 
Conidia muticate 

Pycnidia stellately divided or 

cleft 3. Actinothecium. 

Pycnidia depressed-clypeate, not 

stellate 4. Leptothyrium, p. 529. 

Conidia setulose at each end 5. Tracyella. 

Conidiophores present, cylindric 6. Piggotia, p. 530. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



529 



Pycnidia more or less, clearly cleft length- 
wise 

Pycnidia elongate or lanceolate 7. Leptostroma, p. 530. 

Pycnidia subcircular 8. Labrella, p. 530. 

Pycnidia in a stroma 

Stroma phyllogenous 9. Melasmia, p. 530. 

Stroma growing on animal hairs 10. Trichophila. 




3C' 

Fig. 362.— Lepto- 
thyrium o x y- 
cocci. Four 
spores. After 
Sheai. 



Leptothyrium Kunze & Schweinitz (p. 528) 

Pycnidia superficial or erumpent, dimidiate, scutiform, mem- 
brano-carbonous, black, coalescing or scattered, ostiole variable, 
structure cellular; conidia ovoid-oblong to fusoid. 
Some one hundred species. 

In part=Gnomonia and Gnomoniella. 
L. alneum (Lev.) Sacc. on alder = Gnomoniella 
tubiformis. See p. 274. 

L. pomi (M. & F.) Sacc.i=^«' ^^^ 
Forming minute superficial black spots; pycnidia 
differentiated in late winter, 25-100 ju; conidia el- 
liptic, 12-14 X 2-3 IX. The mycelium of the spots breaks away 
and probably functions as a reproductive body. 

The fungus is common in sterile form on pomaceous fruits but 
the sporing stages are rarely found. 

L. periclymeni Desm., L. acerinum Ktz. and L. buxi Pass, are 
on Lonicera, acer and box respectively. 
L. oxycocci Sh. ^^^ 

Pycnidia black, dimidiate, amphigenous, scattered, subco- 
riaceous- to coriaceous, irregularly subglobose, 
subepidermal, erumpent, rupturing irregularly; 
conidia subfusoid, sometimes slightly curved, 
pseudoseptate, 10-15 x 2.5-3 /x; conidiophores 
simple, straight, tapering, slightly longer than 




Wmm?' 



Fig. 363.— Lepto 

thyrium oxycocci. j-u„ p^nidiq 
Section of a pyc- ^"^ COniQia. 

nidium, showing Qn Cranberry. 

its dimidiate char- _ , , . -r^ ^ 

acter. After L. macrothecium Fcl. 

'^' strawberry disease. 



is said to cause a 



L. peonae Br. & Cav. is on peony leaves. 

L. parasiticum Poll, is on Cereus stems in Italy. 



530 THE FUNGI WHICH CAUSE PLANT DISEASE 

An undetermined species has been reported as a "fly speck" on 
cabbage. ^^^ 

Piggotia Berkley & Brown (p. 528) 

Pycnidia applanate, inequilateral, thin-membranous, later with 
a stellate cap which is thrown off forcibly; conidia elongate or 
cylindric. 

A genus of less than ten species. 

P. astroidea Berk. & Br. parasitizes elm leaves. 

P. fraxini B. & C. 

Perithecia hypophyllous; spores oblong, 5-7 /x long. On ash, 
causing leaf spot. 

Leptostroma Fries (p. 529) 

Pycnidia dimidiate, subsuperficial, applanate, elongate, black, 
more or less hysterioid; conidia ovate, elongate or allantoid. 
In part = Hysteriaceae. There are some sixty species. 
L. larcinum Fcl. on larch = My cosphserella larcina. See p. 249. 
L. piricola B. & S. occurs on the pear; 
L. punctiforme Wallr. on willow. 

Labrella Fries (p. 529) 

Pycnidia black, round, often indefinite; spores long, fusiform, 
or spherical, hyaline, continuous. 

L. piricola Bres. & Sacc. is on pear leaves; 
L. coryli (Desm. & Rob.) Sacc. on Corylus. 

Melasmia Levielle (p. 429) 

Pycnidia dimidiate, carbonous, black, often on an effused black 
stroma; conidia allantoid. 

In part = Rhytisma. Over twenty species. 

M. acerina Lev. is the conidial form of Rhytisma acerinum. 
See p. 158. M. punctata S. & R. and M. salicina Lev. of the two 
corresponding Rhytismas. See p. 158. 



THE FUNGI WHICH CAUSE PLANT DISEASE 531 

Leptostromataceae-Phaeosporae (p. 528) 
Conidia globose to oblong, 1-celled, dark. 

ICey to Genera of Leptostromataceae-Phaeosporae 

Pycnidia separate 

Pycnidia on a dark subicle, radiately de- 
hiscent 1. Asterostomella. 

Pycnidia not on a subicle 

Conidia conglobate, verrucose 2. Discomycopsella. 

Conidia not conglobate, smooth 3. Pirostoma, p. 531. 

Pycnidia in a stroma 
Stroma membranous 

Pycnidia distinct, exserted 4. Peltostroma. 

Pycnidia merely locules, immersed. ... 5. Lasmenia. 
Stroma carbonous; locules many, 

immersed 6. Poropeltis. 

Pirostoma Fries 

Pycnidia separate, shield-shaped, rounded or elongate, leathery, 
conidia globose to ellipsoid. 

A genus of less than five species. 

P. farnetianum Poll, occurs on Pandanus in Italy. 

Leptostromataceae-Hyalophragmiae (p. 528) 
Conidia oblong to fusoid, hyaline, 2 to several-septate. 

Key to Genera of Leptostromataceae-Hyalophragmiae 

Pycnidia astomous or ostiolate, not cleft 
Conidia muticate; pycnidia with creeping 

hyph^e 1. Asterothyrium. 

Conidia ciliate 

Conidia fusoid, 1-ciliate at each end. . 2. Discosia, p. 531. 
Conidia cruciate, each arm 1-ciliate. . 3. Entomosporium, p. 532. 
Pycnidia rimose dehiscent 4. Cystothyrium. 

Discosia pini Heald has been reported as a parasite on pine 
hypocotyls. 



532 THE FUNGI WHICH CAUSE PLANT DISEASE 



Entomosporium Levielle (p. 531) 

Pycnidia depressed, sul)globose, not ostiolate, black; conidia 
4-celled, cruciate, each arm 1-ciliate. 

A genus of three species of parasites. In part=Fabrea. 

E. mespili (D. C.) Sacc. =F. mespih. See p. 150. 

E. maculatum Rev. on pear and quince = F. maculata. See 
p. 149. 

E. thumenii (Cke.) Sacc. occurs on hawthorn. 

Leptostromataceae-Scolecosporae (p. 528) 
Conidia usually hyaline, linear or filiform, continuous or septate. 

Key to Genera of Leptostromataceae-Scolecosporae 

Pycnidia astomous or opening variousl^y 
Pycnidia with a round ostiole; conidia 

catenulate 1. Crandallia. 

Pycnidia astomous or irregularly dehis- 
cent 
Pycnidia with radiate-fimbriate mar- 
gin 2. Actinothyrium. 

Pycnidia not radiate-fimbriate 

Pycnidia of two kinds, small simple, 

and large and loculate 3. Brunchorstia, p. 532. 

Pycnidia of one kind 
Conidia muticate 
• Pycnidia corrugate, not hairy; 

conidia not separating 4. Melophia. 

Pycnidia hairy; conidia separat- 
ing into joints 5. Chaetopeltis. 

Conidia ciliate-penicillate at 

apex 6. Giulia. 

Pycnidia elongate, longitudinally cleft 7. Leptostromella, p. 533. 

Brunchorstia Eriksson 

Pycnidia erumpent, irregular in form, the smaller occurring 
singly, the larger as chambers in a stroma, opening by an irregular 
pore; conidia filiform, septate. A single species. 

B. destruens Erik, on pine=Cenangium abietis. See p. 151. 




THE FUNGI WHICH CAUSE PLANT DISEASE 533 



Leptostromella Saccardo (p. 532) 

Pycnidia at first covered, at maturity apparently superficial, 
depressed convex, subcarbonous, dark colored; conidia bacillar 
or filiform, continuous or sep- 
tate. 

About twenty species, chiefly 
of no economic importance. 

L. elasticae E. & E. 

Spots large, more or less el- 
liptic, whitish, sordid, purplish 
margined; pycnidia epiphyllous, j,,^_ 364.-Lcptostroi^i eiasticse. 
hysterioid, 0.5-0.7 mm.; longi- After stone and Smith, 

tudinally dehiscent; conidia oblong, hj^aline, continuous, 12-15 x 
4-5 fj.; conidiophores 12-15 x 3-4 n; obtuse, subolivaceous. 

The cause of leaf spots of Ficus elastica.-^^^ 

Excipulaceae (p. 479) 

Pycnidia membranous to carbonous, black, cup-shaped, patel- 
late or hysterioid, at first more or less spherical but at length widely 
open, erumpent or superficial, glabrous or hairy. 

Key to Sections of Excipulaceae 

Conidia globose to fusoid, continuous 

Hyaline I. Hyalosporae, p. 533. 

Colored II. Phasosporae. 

Conidia 1-septate, hj^alinc III. Hyalodidymae, p. 53G. 

Conidia 2 to several-septate 

Hyaline IV. Hyalophragmiae. 

Colored V. Phaeophragmiae. 

Conidia filiform or bacillar VI. Scolecosporae, p. 536. 

Excipulaceae-HyalosporaB 

Conidia hyaline, continuous, globose to oblong. 



534 THE FUNGI WHICH CAUSE PLANT DISEASE 



Key to Genera of Excipulaceae-Hyalosporae 

Pycnidia pilose or setose 
Conidia muticate; pycnidia cupulate. ... 1. Amerosporium, p. 534. 
Conidia ciliate; pycnidia cupulate 

Conidia several-ciliate at apex 2. Polynema. 

Conidia 1-ciliate at each end.- 3. Dinemasporium, p. 535. 

Pycnidia smooth or nearly so 

Pycnidia more or less cup-shaped, or dis- 
ciform 
Pycnidia black 

Pycnidia composed of conglutinate 

dark hyphae 4. Godroniella. 

Pycnidia with cellular context 

Pycnidia cup-like when mature, 
sometimes obconoid 
Conidiophores simple 

Pycnidia cup-shaped 5. Excipula. 

Pycnidia terete-conic 6. Catinula. 

Conidiophores branched 7. Heteropatella. 

Pycnidia subglobose, disciform or 
verruciform 
Pycnidia subglobose, irregularly 

dehiscent and coUabent .... 8. Dothichiza, p. 535. 
Pycnidia disciform, often im- 
perfect and covered by 

epidermis 9. Discula, p. 535. 

Pycnidia verruciform; conidia 

mucose-involute 10. Agyriellopsis. 

Pycnidia purple 11. Lemalis. 

Pycnidia hysterioid or valvately gaping 

Pycnidia widely hysterioid 12. Psilospora. 

Pycnidia valvately gaping 

Conidiophores typically branched. . . 13. Sporonema, p. 535. 
Conidiophores simple or none 14. Pleococcuin. 

Amerosporium Spegazzini 

Pj'cnidia subcupulate, setulose, conidia cylindric to ellipsoid. 
Some twenty-five species, chiefly saprophytes. 
A. oeconomicum E. & T. 



THE FUNGI WHICH CAUSE PLANT DISEASE 535 

Spots orbicular, 2-6 mm., white above with a reddish border, 
mostly entirely reddish below; pycnidia epiphyllous, erumpent, 
conic-hemispheric, broadly perforate above, beset with straight, 
spreading, grayish-black, septate bristles, 100-150 x 4 /*; conidia 
oblong-fusoid, 18-27 x 4 /x. 

Very common on cowpea leaves in circular spots, with dark 
pycnidia in concentric circles on white background/^^ 

Dinemasporium Levielle (p. 534) 

Pycnidia cupuliform, superficial, black, with dark bristles; 
conidia elongate or allantoid, with apical spines. 
Some thirty species, chiefly saprophytes. 
D. oryzae Miy. is on rice.^^ 

Dothichiza Libert (p. 534) 

Pycnidia erumpent, roundish, somewhat disculate, irregularly 
dehiscent; conidia elongate or cylindric. In part =Cenangium. 
About eleven species, chiefly saprophytes. 
D. populea S. & B. parasitizes poplar.^"*" 

Discula Saccardo (p. 534) 

Pycnidia disciform-patellate, imperfectly differentiated from 
the substratum; conidia ellipsoid, elongate or cylindric. 
Some twenty-five or thirty species, chiefly saprophytes. 
D. platani (Pk.) Sacc.=Gnomonia veneta. See p. 274. 

Sporonema Desmazieres (p. 534) 

Pycnidia subepidermal, erumpent, at first 
closed, then opening radiately; conidia ovate 
or cylindric. 

Some sixteen species, chiefly saprophytes. 

S. platani Baum on Platanus=Gnomonia Fig. 365. — Sporonema 

ircr,o+o Qoo t^ 97/L oxycocci on cranberry 

veneta. feee p. Z/4. leaf_ After Shear. 

S. phacidioides Desm.=Pseudopeziza tri- 

folii. See p. 148. 

S. oxycocci Sh.'^^ 

Pycnidia amphigenous, excipuliform, thickened at the base, 




536 THE FUNGI WHICH CAUSE PLANT DISEASE 

gradually disappearing above, immersed, erumpent, depressed- 
globose, gregarious or scattered, 50-100 m, sometimes collapsing 
rupturing irregularly by a slit or triangular split; conidia cylindric, 
straight, 17-19 x 3-4 //; conidiophores simple, oblong to subglobose, 
about 34 the length of the spore, or less. On cranberry. 
S. pulvinatum Sh. is also on cranberry. 

Excipulaceae-Hyalodidymae (p. 533) 
Conidia hyaline, 1-septate, oblong or fusoid. 

Key to Genera of Excipulaceae-Hyalodidymae 

Pycnidia discoid or patellate 

Pycnidia discoid, veiled; conidiophores 

simple 1. Discella, p. 536. 

Pycnidia patellate, subsuperficial; conid- 
iophores branched 2. Pseudopatella. 

Pycnidia hysterioid or irregularly gaping 

Pycnidia hysterioid, elongate 3. Scaphidium. 

Pycnidia globose, then irregularly gaping; 

conidia catenulate 4. Siropatella. 

Discella Berkley & Broome 

Pycnidia disco-patellate, imperfectly formed; conidia fusoid 
or oblong. Some twelve or fifteen species, chiefly saprophytes. 

D. cacaoicola A. & S. is on cacao in Africa. 

The Excipulaceae-hyalophragmias, ExcipulacesB-phaeophragmiae 
contain no important parasites. 

Excipulaceae-Scolecosporae (p. 533) 

Conidia typically hyaline, bacillar or filiform, continuous or 
septate. 

Key to Genera of Excipulaceae-Scolecosporae 

Pycnidia separate 

Conidia separating at the joints 1. Schizothyrella. 

Conidia not separating 
Pycnidia discoid, covered, erumpent, 

margin lacerate; conidia filiform. . 2. Protostegia. 



THE FUNGI WPIICH CAUSE PLANT DISEASE 537 

Pycnidia mostly cupulate, not lacerate; 

coniclia hamate 3. Oncospora. 

Pycnidia in a stroma 

Pycnidia pezizoid 4. Ephelis, p. 5.'57. 

Pycnidia superficial 5. Pseudocenangium. 

Ephelis Fries 

Stroma black, subeffused, sclerotioid; pycnidia pezizoid, sunken, 
in the stroma; conidia cylindric to filiform. 

Some seven species, chiefly of no economic importance. 
It is a conidial form of Balansia. See p. 209. 

Melanconiales (p. 479) 

Mycelium internal; true pycnidia never developed, the conidio- 
phores form a stratum; strata typically bearing conidia in acervuli 
which are immersed or erumpent, black or light colored, waxy, 
corneous or even submembranous, accompanied by setae or not; 
conidia variable. 

The common name " anthracnose" is applied to any disease 
caused by a member of this order. 

A single family Melanconiaceae which contains about forty-five 
genera and over twelve hundred species. 

Key to Sections of Melanconiaceae 

Conidia globose to elongate 
Conidia continuous 

Hyaline I. Hyalosporae, p. 538. 

Colored II. Phaeosporas, p. 553. 

Conidia 1-septatc 

Hyaline III. Hyalodidymae, p. 555. 

Colored IV. Phaeodidymae, p. 556. 

Conidia 2 to many septate 

Hyaline V. Hyalophragmiae, p. 556. 

Colored VI. Phaeophragmiae, p. 557. 

Conidia muriform, dark VII. Phaeodictyae. 

Conidia long-cylindric to filiform VIII. Scolecosporse, p. 561. 

Conidia stellate IX. Staurosporae. 



538 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Melanconiaceae-Hyalosporse (p. 537) 
Conidia hyaline, 1-celled, globose to oblong, rarely dilute colored. 

Key to Genera of Melanconiaceae-Hyalosporae 

Conidia muticate 
Masses, or acervuli, not setose 
Conidia not catenulate 
Conidia not allantoid 
Masses bright colored, subtremel- 

loid 1. Hainesia. 

Masses gray to black, rarely 

bright colored, waxy or horny 

Growing, for the most part, on 

leaves or fruits 2. Glceosporium, p. 539. 

Growing usually on twigs of trees 

or shrubs 3. Myxosporium, p. 546. 

Masses black, discoid, horny 4. Melanostroma. 

Conidia allantoid 5. Naemospora, p. 547. 

Conidia in chains 
Masses oblong, hysterioid, dark, 

hard 6. Hypoderinium, p. 547. 

Masses discoid, pulvinate or conoid 

Masses bright colored, soft 7. Myxosporella. 

Masses dark to black 
Conidiophores repeatedly 
branched 
Masses discoid; conidiophores 

dichotomous 8. Blennoria. 

Masses depressed-pulvinate; 

conidiophores verticillate 9. Agyriella. 
Conidiophores simple 

Masses scutellate, olive or 

ashen 10. Myxormia. 

Masses truncate, black below, 

pale above 11. Bloxamia. 

Masses setose at margin; conidiophores 

short, fasciculate 12. ColIetotrichum,p.547. 

Conidia aristate with a branched awn at 

apex 13. Pestalozziella. 



THE FUNGI WHICH CAUSE PLANT DISEASE 539 

Gloeosporium and Colletotrichum are prominent in pathology as 
the "anthracnose fungi" and cause many important diseases. The 
two genera, separated only by the occurrence or non-occurrence of 
setae, contain many species which have been transferred from one 
of these genera to the other on this character, which is to some ex- 
tent a variable one depending upon the supporting medium, con- 
ditions of growth and the particular strain of the fungus under 
observation. 

Many form-species have been described solely on a basis of 
the hosts affected. Subsequent culture study, and cross inocula- 
tion has often failed to sustain these species so that many forms 
that were formerly considered as distinct are now grouped under 
one name. No satisfactory disposition of these forms can be made 
until their ascigerous stages are known and compared and their 
biologic relations investigated. 

Such work as has been done (see page 267) leads rather to con- 
solidation than to segregation of species. 

For sake of clearness and convenience, mention is made below 
of many form species of these two genera under their old names, 
though the evidence now is that in many instances they should be 
consolidated with other species. 

Gloeosporium Desmazieres & Montaigne (p. 538) 

Conidial layer subepidermal, disciform or pulvinate, usually 
erumpent, pale or fuscous; conidia ovate, rarely oblong; conidio- 
phores needle-shaped. 

In part=Glomerella, Pseudopeziza, Gnomoniella, Gnomonia, 
Trochila, Physalospora, Calospora. 

There are over three hundred species of parasites, many of 
them very important pathogens. The spores in germination 
commonly form dark colored, thick-walled chlamydospores and 
usually l)ecome 1-septate. 

G. rufomaculans (Berk.) Thiim. on a large variety of hosts = 
Glomerella rufomaculans. See p. 264. 

G. melengonea E. & H. is reported on egg-plant fruits in New 
Jersey ;^^ G. orbiculare Berk, on cucurbs; 

G. fructigenum Berk, on many fruits. 

G. laeticolor Berk, on peaches and apples and G. versicolor 



540 



THE FUNGI WHICH CAUSE PLANT DISEASE 




THE FUNGI WHICH CAUSE PLANT DISEASE 541 

B. & C. on peaches are probably all identical with Glomerella 
rufomaculans. 

G. salicis West, on Salix=Pseudopeziza salicis. See p. 148. 

G. piperatum E. & E. on pepper = Glomerella piperata. See 

p. 269. 

G. cylindrospermum (Bon.) Sacc. on Alnus = Gnomoniella tubi- 

formis. See p. 274. 

G. vanillse Cke. on orchids =Calospora vanillse. See p. 280. 
G. macropus Sacc. on Cattleya=Physalospora cattleya. See 

p. 253. 

G. cinctum B. & C. on orcliids=Glomerella cincta. See p. 269. 
G. paradoxum (de Not.) Fcl. on Hedera=Trochila craterium. 

See p. 157. 

G. cingulatum Atk. on privet = Glomerella cingulata. See 

p. 268. 

G. psidii Dei. on guava= Glomerella psidii. See p. 270. 

G. atrocarpi Del. on Atrocarpus= Glomerella atrocarpi. See 

p. 273. 

G. nervisequum (Fcl.) Sacc. on sycamore =Gnomonia veneta. 

See p. 274. 

G. ribis (Lib.) M. & D. on Ribes=Pseudopeziza nbis. See 

p. 148. 

G. bicolor M. Cal. occurs on grapes in Australia. 

G. ampelophagum (Pass.) Sacc.^^^"^^^ 

Spots subcircular often confluent, from cortex of the berry, cen- 
ters gray; margin dark or red. Acervuli subepidermal, minute, col- 
lected; conidia oblong, ellipsoid or ovoid, 5-6 x 2-3 /x, hyaline. 

Small dark spots are produced on fruit, leaf or cane of grape. 
These later enlarge and show white centers with dark or even red 
borders. The mycelium lies just below the epidermis. On shoots 
the cambium is killed and cankers develop. Two kinds of spores 
have been found by Viala and Pacottet^^^ one very small and linear, 
the other larger and in Phoma-like pycnidia. Common in the 
eastern United States and Europe. 

G. depressum Penz. is on Citrus. 

G. spegazzinii Sacc; and G. intermedium Sacc. grow on Citrus 
fruits; G. citri Mas., G. hendersonii B. & Br. on oranges causing 
leaf scorch in England, and Trinidad. 



542 



THE FUNGI WHICH CAUSE PLANT DISEASE 



G. variabile Laii. grows on Ribes alpinum. G. curvatum 
Oud. is described as a currant parasite. 
G. malicorticis Cor.^^ 

Caulicolous; spots brownish, slightly depressed, irregular in 
outline; acervuli minute, erumpent; conidia elliptic, curved, 

hyaline or greenish-tinged, 
granular, 24 x 6 ju- 

On apples in northwestern 
United States. Neofabrea has 
been reported as genetically 
connected. ^^^ 

G. cydoniae Mont, is re- 
corded as a parasite on the 
quince. 

G. musarum C. & M. is a 
common wound parasite on 
bananas. 

Acervuli innate; erumpent, 
gregarious, rose-tinged; conidia 
elongate-ellipsoid, ends 
rounded, 10-12 x 4-5 fx, gran- 
ular. A variety, importatum, 
is also recognized. 
G. diospyri E. & E. 
Acervuli on yellowish dis- 
colored areas, innate, erumpent, epiphyllous, on the leaf veins, mi- 
nute, tuberculiform, pale; conidia ovate, granular, 6-14 x 5-7 /x. 
On persimmon. 
G. fragariae (Lib.) Mont. 

Spots indeterminate, red, epiphyllous; acervuli applanate, 
rugulose, black; conidia cylindric, 4 to 5-guttulate. 
On strawberries but not usually troublesome. 
G. amygdalinum Brizi.^^^ occurs on the green fruit of the al- 
mond in Italy. 

G. venetum Speg.^^* "^'^^^ 

Caulicolous or foliicolous; spots orbicular or elliptic, border 
raised, darker, 2-3 mm. in diameter; conidia oblong, elliptic, 
5-7 x 3 /i, in mass amber-colored. 




Fig. 367. — G. malicorticis; a, acervulus; 
E, germinating spore. After Cordley. 



THE FUNGI WHICH' CAUSE PLANT DISEASE 543 

The fungus occurs on all aerial parts of the raspberry and is 
wide-spread in Europe and America causing serious disease. On 
canes small purple spots first show near the ground, enlarge and 
soon develop ashen centers. The leaf spots are small, often 
scarcely 1 mm. in diameter. 

G. mangiferae Hen. is found on mango leaves in Cuba 
and other West Indian Islands. 

G. olivarum d'Alm. parasitizes olive fruit in Europe. 

G. minus Sh. is on cranberry. ^^" 

G. myrtilli All. is injurious to Vaccinium myrtillus. 

G. cofifeanum Del. occurs on coffee in Java; 

G. pestis Mass. on yam leaves in Fiji. 

G. trifolii Pk.i'^^-i^^ 

Spots subcuticular, brown, suborbicular, concentrically zonate; 
conidia oblong to cylindric, obtuse, 15-23 x 4-6.3 fi. 

The fungus was first observed in America and what was regarded 
as the same was later seen in Europe as the cause of dying of stems 
and leaves of clover. 

G. caulivorum Kirch. ^^' 

Caulicolous, spots forming long dark streaks, more or less sunken, 
blackish-bordered; acervuli minute; conidia curved, more or less 
pointed, 12-22 x 3-5 ju. 

This was said by Kirchner (see ^^^) to be the cause of the more 
serious European anthracnose affecting stem, fruit and leaf of 
clover. Fulton ^^^ in 1910 reported it in America and showed that 
pure cultures of the fungus readily produced infection in wounds or 
even on un wounded succulent parts when in humid air. The conidia 
have been knowTi to live twelve months. 

G. morianum Sacc. is on alfalfa. 

G. medicaginis E. & K. 

Acervuli scattered, innate, blackish, rather large, visible on both 
sides the leaf, opening below; conidia oblong, cylindric, granular, 
subhyaline, more or less narrowed at the middle, 15-20 x 3-4 n. 

On withered leaves and stems of alfalfa, defoliating the lower 
part of the stem. 

G. manihotis Hen. is found on Cassava in Africa. 

G. lagenarium (Pass.) Sacc. on cucumbers is probably identical 
with CoUetotrichum lindemuthianum. 



544 THE FUNGI WHICH CAUSE PLANT DISEASE 

G. concentricum Grev. causes spotting of leaves of cabbage, 
cauliflower, etc. 

G. cattleyae (P. & D.) Sacc. grows on leaves of Cattleya; 
G. dianthi Cke. on carnation in England. G. clematidis Sor. is 
found on cultivated clematis stems j^''^ 

G. rosae Hals.^^ is reported by Halsted on rose canes causing 
injury similar to that of G. venetum on the raspberry. 

G. mezerei Cke. is on Daphne. 

G. affine Sacc. grows on various orchids and Hoya. G. oncidii 
Oud. on Oncidium. 

G. euphorbias Hals, is on clusters and stems of spurge."^ 

G. stanhopeicola Hen., G. laeliae Hen. and G. pallidum Karst. 
& Har. are on orchids; G. helicis (Desm.) Oud. on English ivy. 

G. cactorum Ston. occurs on a number of species of cacti; 

G. beyrodtii Klitz on Vanda; 

G. opuntiae E. & E. on Opuntia; 

G. elasticae C. & M. on Ficus; 

G. bruneum Fetch, and G. alborubrum Fetch, on Hevea. 

G. rhodendendri Br. & Cav. forms yellow spots on various 
species of Rhododendron. 

G. aquilegiae Thiim is on Aquilegia. 

G. violaB B. & Br.i8 

Spots pale, becoming whitish; acervuli very thin, solitary; 
conidia yellowish. Causing leaf spots on cultivated violets. 

G. cytisi B. & Br. is on laburnum; 
« G. bidgoodii Cke. is on Oncichum; 

G. pelargonii C. & M. on Felargonium. 

G. crotonis Del. occurs on Codiaum. 

G. soraurianum All. also on Codiseum leaves and described as 
a dangerous parasite is perhaps identical with G. crotonis. 

G. anthuriophilum Trinch. causes spots on Anthurium leaves. 

G. begonias Magnag. is on begonias in Italy. 

G. fagicolum Fass. is widespread and destructive to beech 
in Germany. 

G. umbrinellum B. & Br. is found on Quercus; 

G. inconspicuum Cav. on elm; 

G. theas-sinensis Miy. and G. theas Zimm. on tea in Japan and 
Africa. 



THE FUNGI WHICH CAUSE PLANT DISEASE 545 

G. allescheri Bres. and G. nanoti P. & D. (xx-ur on 
Palms. 

G. tiliaeOud. is a serious parasite on the twigs, petioles and leaves 
on the linden in Denmark. 

G. tiliaceum (AU.)^''^ said to be distinct from the above occurs 
in Germany on Tilia. 

G. juglandis (Lib.) Mont, causes a common, and serious leaf 
blight of the butternut. ■^•'^ 

G. fagi (D. & R.) West is on Fagus; 

Spots subcircular, fuscous above, olivaceous, vitreous be- 
neath; acervuh small, prominent, honey-colored; conidia oblong 
ovate, 15-20 x 7-8 n, minutely 1 to 3-guttulate; conidiophores 
fasciculate, cylindric, fuscous. 

G. apocryptum E. & E. causes a nursery disease of maples 
and of )30x elder. ^""^ 

Acervuli numerous, minute, mostly hypophyllous, on dead areas 
of the leaf; conicUa very variable in size, 5-12 x 23/2-5 n, oblong 
to narrowly elliptic. 

G. betularum E. & M. 

Spots rounded, 2-3 mm., blackish margined; acervuli amphig- 
enous, brownish, 120-140 fx, becoming cupulate; conidia hyaline, 
obovate, 9-10 x 5-6 /x- 

It is common on leaves of American birches. 

Other common species on deciduous trees are: 

G. tremulas (Lib.) Pass, on Populus; 

G. betulinum West, on beech; 

G. alneum West, on alder; 

G. carpini (Lib.) Desm. on Carpinus; 

G. coryli (Desm) Sacc. on Corylus; 

G. quercinum West, on oak; 

G. nervicolum Massal on oak. 

G. kawakamii Miy. is found on Paulownia in Japan causing 
witches' brooms. 

G. saccharini E. & E. 

Acervuli minute, numerous; spores oblong-fusoid, 6-7 x 1.5-3 n, 
hyaline, continuous. On maple. 

G. caryss E. & D. =Gnomonia caryse.^*^ 

Spots suborbicular, 1-2 cm., margin subdefinite; acervuli 



545 



THE FUNGI WHICH CAUSE PLAxNT DISEASE 



hypophyllous, numerous, 75-150 n; spores allantoid, continuous, 
7-10 X 1.5-2 /I. On Carya. 

G. berberidis Cke. 

Hypophyllous; acervuli collected, numerous; spores ovoid, 
5 X 3 IX. On Barberry. 

G. tamarindi Hem. is on tamarinds, in Africa. 

G. canadense E. & E. 

Spots amphigenous, center pale, border brownish; acervuli few, 




Flu. 368. — M. corticolum, on apple twig. Alter 
Edgerton. 

180-200 m; spores ovate-oblong, hyaline, 10-14 x 3.5-4.5. 
On white oak. 



Myxosporium Link (p. 538) 

Acervuli immersed or superficial, indefinite, pallid or reddish; 
conidia ovate, hyaline or pale, conidiophores slender-cylindric. 

Some seventy species, some of which are important pathogens. 

In part=Gnomonia. See p. 274. 

M. valsoideum (Sacc.) All. on sycamore =Gnomonia veneta. 
See p. 274. 

M. corticolum Edg. 

Acervuli erumpent, originating under several layers of cortex, 
1-2 mm. in diameter, scattered over the diseased area; conidia 
straight or curved, cylindric, very densely granular, 18-36 x 6-9 
M, oozing out of the pores in white cirri; conidiophores very 
short. Very similar to an immature Sphseropsis malorum but 
considered distinct by Stewart and his associates. ^^ 

It forms bark cankers in pear and apple in America. 



THE FUNGI WHICH CAUSE PLANT DISEASE 547 

M. longisporum Edg.^''^ 

Acervuli erumijent, subcorticular, variable in size up to 1.5 mm., 
scattered over the host in poorly defined rows; conidia straight 
or curved, 30-48 x 12-15 n, oozing out in white cirri; conidio- 
phores very short. 

On twigs of Liriodendron. 

Other parasitic species are: 

M. piri Fcl. on pear; M. mali Bres. on apple; M. abietinum 
Rost. on conifers; M. devastans Rost. on beech; M. lanceola S. & 
R. on oak; M. carneum Lib. on beech twigs. 

Naemaspora Persoon (p. 538) 

Acervuli subgelatinous, indefinite, bright colored; conidia 
allantoid, short, with a bristle at each end. 

N. crocea (Bon.) Sacc. is reported by Massee as the cause of 
die-back of peach shoots in England. ^^^ 

Hypodermium Link (p. 538) 

Acervuli subcuticular, erumpent, elongate, black; conidia ovate- 
oblong, catenulate. 

H. orchidearum Cke. is on Cymbidium. 

Colletotrichum Corda (p. 538) 

Acervuli innate erumpent, discoid or elongate, dark, surrounded 
with long black setae; conidia terete to fusoid; conidiophores short. 

The genus is distinguished from Gloeosporium by the presence 
of setae, a somewhat unreliable character. See p. 539. 

In part=Glomerella and Pseudopeziza. See pp. 264, 147. 

Some eighty species, several of them very important plant path- 
ogens. 

C. gossypii Sout. on cotton =Glomerella gossypii. See p. 271. 

C. cincta Ston. on orchids =Glomerella cincta. See p. 269. 

C. rubicolum E. & E. on red raspberry =Glomerella rubicolor. 
See p. 270. 

C. lindemuthianum (Sacc. & Magnus) Briosi & Cavara.^*' ^^°' 



548 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Spots subelliptic to irregular, depressed, brownish; acervuli 
scattered, surrounded by a few not very conspicuous black seta?; 
conidia oblong, ends rounded, straight or curved, 15-19 x 3.5-5.5 
;u; conidiophores cylindric, simple, 45-55 ju. 

This fungus, generally known as C. lindemuthianum, is accord- 



^nnmcmse Conker 




Starcli Grains 



Fig. 369. — C. lindemuthianum. Showing relation of the fungus 
to the tissues of the bean. To the left above is a diagram of 
a section across a bean pod through a canker. The drawing 
below is a much enlarged largely diagrammatic view of a por- 
tion of this same section. It shows how the mycelial threads 
of the fungus may penetrate the seed coat and enter the 
starchy tissue of the seed, there to remain dormant until the 
following sea.son. On the left is a spore germinating and pene- 
trating the epidermis. To the right a magnified view of spores, 
one germinated. After Whetzel. 



ing to the cultural studies of Shear & Wood (see p. 267), probably 
a variety of Glomerella rufomaculans. See p. 264. 

On the bean it attacks stems, leaves, cotyledons, or the pods, 
producing sunken spots of dead tissue which bear the numerous 
pink acervuli. It has l3een sho■\^^l that the mycelium on the fruit 
may penetrate through the pericarp and into the seeds beneath 
and there hibernate. 

C. lagenarium (Pers.) E. & H. ^^^ is probably identical with 
C. lindemuthianum. It is described as the cause of spots on fruit 
leaves and stems of cucumbers, watermelons, squash, pumpkins 
and citron. 

C. oligochaetum Cav. grows on cucurbs, attacking all parts. ^^^ 
Probablv=C. lindemuthianum. 



THE FUNGI WHICH CAUSE PLAxNT DISEASE 549 

C. carica S. & H.'^' '^^ 

Acervuli brown, becoming black, hemispherical, numerous, 
small, 85-250 ju, bearing 1-12 (or often 0) long, slender, irregular 
setae which are dark throughout, acute, rigid, septate, 2-6 x 22- 
106 iJL, conidia regular, oblong, obtuse, 3.5-6.6 x 8.7-20; conidio- 
phores slender, 1-2 x 45 /x, hyaline. 

It is the cause of a decay of figs in the United States. 

C. ampelinum Cav. is on grape leaves. 

C. glceosporioides Penz. 

Acervuli sparse or scarcely gregarious, subepidermal, erumpent, 
dark, cylindric, setae continuous or few-septate, dark colored, 
40-90 X 5-6 fji, conidia cylindric, straight, 16-28 x 4-6 /x; co- 




70. — C. carica. 5, conidiospores, spores and seta', 1, lilac 
produced on germ tubes. After Stevens & Hall. 

nidiophores densely fasciculate, cylindric, rounded apically, 
tenuous, 18-25 x 4-5 ju. 

It causes "wither tip" of orange, pomelo and lemon, ^^"'^^^ spots 
on citrus leaves, lime canker, and anthracnose of stem and flower 
with great financial loss in Florida, West Indies, South America, 
Australia, Malta and many other localities. 

In "wither tip" the fungus enters through the terminal bud or 
from leaves. On lemons attack is through bruises. Acervuli are 
found on leaf, twig or fruit, breaking through the epidermis. 
Cross inoculation on the various hosts and with the different forms 
of the disease demonstrated the identity of all. Smith ^^^ has 
questioned the casual relation of this fungus as regards "wither- 
tip" as it occurs in California. 

C. falcatum Went. 

Acervuli poorly defined, setae irregularly arranged, cuspidate, 



550 THE FUNGI WHICH CAUSE PLANT DISEASE 

100-200 X 4 /i, brownish; conidia falcate, 25 x 4 /i; conidiophores 
ovoid, 20 X 8 fx., hyaline to fuscous. 

This is believed to be the chief cause of the red rot of sugar- 
cane. ^^^ It was reported in the United States by Edgerton,^^^ 
also b}'' Stevens. ^^® Inoculation experiments indicate that it is 
distinct from C. lineola, on sorghum and Johnson grass, which it 
resembles morphologically. 

C. cereale Manns. ^^^ 

Spots circular to ovoid, 30 mm.; acervuli dark brown, or black; 
setse few or many, dark brown to black, at base 6-8 /x thick, 
tapering to a length of 60-120 n, continuous or 1 to 2-septate; 




Fiu. 371. — C. cereale, acervulus showing mycelium, sete, conid- 
iospores and spores. After Manns. 

conidia 18-26 x 3-4 ju, spindle to boat-shaped, 2 to several- 
guttulate; conidiophores, very short, 12-6 x 1-2 ix. 

This fungus is parasitic on the roots, stems, blades and spikes 
of rye, wheat, oats, barley, emmer, orchard grass, timothy, blue 
grass and chess. The disease causes a premature ripening and 
shrivelling of the grain. Superficially the diseased heads present 
the same appearance as those attached bj' scab (Fusariose) but 
no pink over-growth is present, nor is the presence of the disease 
always apparent, as it was found on numerous heads of grain which 
appeared to be healthy. Morphological studies indicate that all 
the hosts mentioned above are affected by the same fungus. This 
was confirmed by cross inoculations in the case of wheat and 
emmer. 



THE FUNGI WHICH CAUSE PLANT DISEASE 551 

C. trifolii Bain.i7s-i8o 

Spots dark, depressed; aeervuli erumpent, scattered or gre- 
garious; conidia straight, ends rounded, 3-4 x 11-13 (jl; conidio- 
phores cylindric or fusoid, hyaline; setae few or many, continuous 
or uniseptate, dark, paler apically, 4-7 x 39-62 n, sinuous, or 
nodose. 

It occurs as an anthracnose producer on stems, rarely on leaves, 
of clover and alfalfa causing very serious injury. In general ap- 
pearance it is much like Gloeosporium caulivorum. 

C. spinaciae E. & H.^" 

Spots roundish, dirty-white, or greenish, 2-4 mm., with a slightly 
raised border; aeervuli amphigenous, punctiform, 40-75 fj., with 
3-12 erect or spreading bristle-like setae, 60-75 x 4-4.5 fx, sub- 
bulbous at base, subhyaline, subacute above, dark brown below; 
conidia subfalcate, fusoid, 2 to 4-guttulate, 14-20 x 2.5-3 ju, ends 
subacute; conidiophores short. 

It produces blotches on spinach leaves. 

C. phomoides (Sacc.) Ches.^^' ^e. 154-157. isi 

Spots depressed, circular, slightly discolored, center black, 
5-10 mm., later irregular and confluent; aeervuli abundant, 
densely gregarious, rusty brown to black, applanate, 95-150 n; 
setffi abundant, fuliginous, generally curved, septate, 65-112 /x; 
conidia oblong, 16-24 x 4 n, ends subacute; conidiophores 
short, slender, 30-40 n high, arising from a well developed 
stroma. On tomato. 

This is a common cause of ripe rot of tomatoes. The fungus was 
studied in culture by Stoneman ^^ who reported it as somewhat 
different from G. rufomaculans, though Edgerton ^^® thought the 
apple and tomato forms the same. Work by Gueguin ^^^ throws 
doubt on the American form on tomato being identical with the 
European form known as G. phomoides. Chester ^^^' ^^- has 
reported what he regarded as the last species as setigerous. 

C. nigrum, E. & H.^^- ^^ 

Spots blackish, depressed; decaying; aeervuli numerous, su- 
perficial; setae numerous, slender, setae pointed; conidia ob- 
long. 

This form which appears quite different from G. piperitum was 
described from New Jersey by Halsted. 



552 THE FUNGI WHICH CAUSE PLANT DISEASE 

C. malvarum Br. & Casp.^^^ (-=c. althgea.) 

Epiphyllous and caulicolous; spots brown, sunken; acervuli 
erumpent; setae dark brown, abundant, 1 or 2-septate, usually 
colorless below, 60-109 x 3-5 jx, appearing after the conidio- 
phores which are colorless, cylindric, tapering slightly and apically 
rounded, slightly longer than the conidia; conidia irregular, oblong, 
granular, flesh-colored in mass, 11-28 x 5 ^t. 

It is described by Southworth ^^^ as the cause of anthracnose of 
the hollyhock. The fungus closely resembles C. -lindemuthianum 
but cross inoculations on the bean failed to produce disease though 
on hollyhock inoculations succeeded easily. 

C. schizanthi Jensen & Stewart was found on greenhouse 
Schizanthus plants in Ithaca.^^^ 

C. agaves Sacc. 

Spots pale; acervuli conic; setse few, 90-100 x 5-6 n, brownish 
ochraceous, 2 to 3-septate, conidia 22-26 x 4-5 ju; conidiophore 
subramose, fuscous at base. On sisil hemp and agave.^^^ 

C. bletiae Hals, fs on Bletia. 

C. violae-tricoloris R. G. Sm.i^^^^^ 

Spots pale-yellow on leaves. Dead areas on petals occur with 
more or less deformity of blossom. Spots at first orbicular and 
definite, later confluent and irregular, acervuli numerous, 50- 
150 ju, often confluent; stroma usually poorly developed; setae 
mostly single or in pairs, 20-70 ^t, deep brown, 1 to 2-septate, 
tapering gradually to a point; conidia oblong or slightlj'' curved, 
ends blunt, 20 x 5 m; conidiophores short, hyaline. 

It causes spotting of pansy leaves in several states and leads 
to failure to bloom. 

C. anthurii Del. occurs on Anthurium; 

C. luxificum H. & D. on cacao in the West Indies; 

C. elasticae (C. & M.) Koo. on Ficus. 

C. primulae Hals.-^ is reported as causing a leaf disease of the 
primrose. 

C. kentiae Hals, is on palms. ^^ 

C. omnivorum Hals. 

Spots dry, irregular in outline; conidia 20-28 x 3-5 n, falcate; 
setae elongate, acute, black. 

On Aspedistra and other plants.-'' 



THE FUNGI WHICH CAUSE PLANT DISEASE 553 

C. camelliae Mas. is on tea. 

C. antirrhini Stcw.^^*^ 

Spots depressed, elliptic or orbicular, often confluent, 3-10 mm, 
acervuli numerous, crowded; stroma well developed; conidia 
16-21 X 4 /i, straight or curved, ends rounded; conidiophores 
short; setse abundant, dark brown, 50-100 n, simple," mostly 
straight and tapering uniformly to a subacute point. 

It attacks the stems and leaves of the cultivated snapdragon 
producing sunken spots. 

C. cyclamenae Hals, is on Cyclamen; 

C. dracaenae Hals, on Dracaena; 

C. cofifeanum N. is on coffee; ^^^ 

C. heveae Fetch, on Hevea in India; 

C. cradwickii Banc, on cacao pods; 

C. brachytrichum Del. on cacao leaves; 

C. theobromae A. & S. and C. theobromicolum Del. are on 
cacao. 

C. incarnatum Zimm. is on Hevea and vanilla; 

C. macrosporum Sacc. on vanilla; 

C. pollaccii Ma^Tiag. on Japanese loquot in Italy; 

C. hedericola Lau. on Hedera. 

Undetermined species of Colletotrichum have been reported 
on asparagus, ^^ carnation,^'' pear,^^ and many other hosts. 

Melanconiaceae-Phaeosporae (p. 537) 
Conidia dark, continuous, globose to oblong or fusoid. 

Key to Genera of Melanconiaceae-Phaeosporae 

Conidia solitary on the conidiophores 

Conidia globose or oblong 1. Melanconium, p. 554. 

Conidia fusoid, often arcuate 

Conidiophores not swollen at base. ... 2. Cryptomela. 

Conidiophores swollen at base 3. Basiascum. 

Conidia in chains 

Conidial chains separate 4. TruUula, p. 554. 

Conidial chains in a niucose head 5. Thyrsidium. 



554 THE FUNGI WHICH CAUSE PLANT DISEASE 



Melanconium Link (p. 553) 

Acervuli subcutaneous, conic or discoid, black; conidia elongate 
to globose-oblong, erumpent in black masses; conidiophore sim- 
ple. In part=Trichosph8eria. See p. 228. 
More than one hundred fifty species. 
M. fuligineum S. & V. Cav.^^ 

Acervuli scattered or gregarious, at first gray-cinereous, then 
brownish, subepidermal, erumpent; conidia ovoid to ellipsoid, 
inequilateral, acute, 9-12 x 4-6 ix, olive, guttulate; conidiophores 
filiform, from a well developed stroma. 

It causes the important bitter rot of ripening grapes, especially 
the white varieties, occurring also on shoots 
and peduncles. Acervuli appear on the 
surface of the rotted berries. The myce- 
lium penetrates even to the seeds. 

Southworth suggested in 1891 ^^^ that 
this and Gloeosporium are congeneric but 
Atkinson ^^° who studied the fungus in pure 
1^ culture thinks them generically distinct. 
Fig. 372.— m. fuligineum. Noack ^^^ who studied what he regarded as 

After Atkinson. ., , • i -ht <• i- • ,i ■ •, • 

the typical M. luligmeum says that it is 
preceded by and belongs to a Gloeosporium-form. 

M. pandani Lev. is a common parasite on Pandanus in green- 
houses, killing the branches. 

M. sacchari Mass.^-^ 

Acervuli numerous, collected in indeterminate pallid orbicular 
spots; conidia cylindric, 10-15 x 3-4 n, straight or slightly curved, 
olivaceous, smooth. 

In leaves, sheaths and culms of sugar cane. The cause of the 
rind disease. 

TruUula Cesati (p. 553) 

Acervuli subcuticular, erumpent, discoid-pulvinate, or conical- 
depressed, black; conidia oblong-cylindric, catenulate; conidio- 
phores long, bacillar, simple or branched. 

Some twenty species, of trifling economic importance. 

T. vaniUae Hen. is on vanilla in Africa. 




THE FUNGI WHICH CAUSE PLAx\T DISEASE 555 

Melanconiaceae-Hyalodidymae (p. 537) 
Conidia hyaline, 1-septate, ovoid to fusoid. 

Key to Genera of Melanconiaceae-Hyalodidymae 

Conidia mutic 

Saprophytic, on stems and fruits 1. Septomyxa. 

Biogenous, typicahy on leaves 2. Marssonia, p. 555. 

Conidia 3 to 4-ciliate at each end 3. Gloesporiella. 

Marssonia Fisch 

Acervuli globose-discoid, pale, conidia ovate to elongate. In 
part =Gnomonia, Trochila, Pseudopeaiza, 

Some seventy-five species, all leaf parasites, several of eco- 
nomic importance. 

M. castagnei (D. & M.) Sace. on Populus = Trochila popularum. 
See p. 157. 

M. juglandis (Lib.) Sacc. on walnut =Gnomonia 
leptostyla. See p. 275. 

M. populi (Lib.) Sacc. 

Spots suborbicular, epiphyllous, separate or con- 
fluent, browTi, darker margined, acervuli convex _, ^_., ,, 

' ' . . . Fig. 3/3. — M.per- 

to applanate, fulvous; conidia obovate to subpyri- forans, conidio- 
form, 20 x 12 n, constricted at the septum, spor/sf ^AfVer 
straight or curved. Selby. 

It is common on leaves of Populus as the cause of blighting 
of lateral twigs. It is injurious in nurseries.^® 

M. panattoniana (Berl.) Mag. is found on lettuce in Italy; 

M. secalis (Oud.) Mag. on rye; 

M. martini S. & E. on oak; 

M. potentiilae (Desm.) Fisch as the cause of a disease of the 
strawberry in Europe. 

M. rosae Trail causes premature fall of rose leaves. 

M. perforans, E. & E.^^s 

Spots small; irregular, 1-2 mm., pale, soon deciduous; acervuli 




556 THE FUNGI WHICH CAUSE PLANT DISEASE 



(^ 





100-120 n, or by confluence larger; 
conidia abundant, clavate or wedge- 
shaped, 11-15 X 2.5-3 Ai. 

The cause of leaf perforations of 
/^^ lettuce. 
A (r\ M. violae.(Pass.) Sacc.^^^ 

^ 1 (// Discoloration of the host slight; 

._-^_^ JII!^^ acervuU numerous, scattered, small; 

~ conidia curved, or straight, 15-18 x 

5-6 M> septum usually excentric. 
Small spots are produced on violet 

FiQ. 374. — Marssoniu violae. 

Spores and conidiophores. leaVCS. 

After Jones and Giddings. -^^ medicaglnis Vors. is on alfalfa. 

Melanconiaceae-Phaeodidymae (p. 537) 
Conidia dark, 1-septate, ovoid to fusoid. 

Key to Genera of Melanconiaceae-PhaeodidymaB 

Conidia solitary 

Conidia muticate 1. Didymosporium, p. 556. 

Conidia 1 to 3-ciliate at apex 2. Neobarclaya. 

Conidia catenulate, connected by hyaline 

isthmi 3. Bullaria. 

Didymosporium Nees 

Acervuli rounded or elongate, covered, erumpent; conidia elon- 
gate or fusoid. A genus of less than twenty species. 
D. salicinum Vuill is on poplar. 

Melanconiaceae-HyalophragmiaB (p. 537) 
Conidia hyaline, 2 to several-septate, oblong to fusoid or clavate. 

Key to Genera of Melanconiaceae-Hyalophragniiae 

Conidia separate 
Conidia muticate 
Conidia oblong or fusoid, masses usually 

pale 1. Septogloeum, p. 557. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



557 



Conidia long-clavatc; masses dark. ... 2. Rhopalidium. 
Conidia 1 to several-ciliate, usually at the 

apex 3. Pestalozzina. 

Conidia united at base into a radiate or stel- 
late group 4. Prosthemiella. 



Septogloeum Saccardo (p. 556) 

Acervuli very small, subepidermal, erum- 
pent, pallid; conidia oblong. Some twenty- 
five species of leaf parasites. 

S. hartigianum Sacc. attacks maple, killing 
very young twigs. 

S. ulmi Fr. is found on elm leaves =Phylla- 
chora ulmi. (?) 

S. mori Lev. on mulberry = My cosphserella 
mori. (?) 

S. cydoniae (Mont.) Pegl. is on the 
quince; 

S. manihotis Zimm. on manihot in Java. 

S. arachidis Rac. is seriously injurious to ^ 
the peanut in Java.^^^ 

S. profusum E. & E. is found on Corylus; 

S. fraxini Hark, on ash. 




I G. 375. — Septo- 
gloeum acerinum, 
conidiospores and 
conidia. After Sac- 
cardo. 



Melanconiaceae-Phaeophragmiae (p. 537) 
Conidia dark, 2 to several-septate, oblong to cylindric. 



Key to Genera of Melanconiaceae-phasophragmiae. 

Conidia mutic 

Conidia separate, not in chains 

Conidia oblong or elongate, not stellate 
Conidia curved-attenuate, i. e., hya- 
line-rostrate 
Conidia dark, except the hyaline 

beak 1. Scolecosporium. 

Conidia with 2 inner cells opaque, 

others clear 2. Toxosporium, p. 558. 



558 THE FUNGI WHICH CAUSE PLANT DISEASE 

Conidia oblong, not rostrate 

Conidia cirrhose protruded. ...... 3. Stilbospora. 

Conidia not protruded 4. Coryneum, p. 560. 

Conidia stellate-lobed, lobes several- 
septate 5. Asterosporium 

Conidia in chains 
Conidia connected with filiform isthmi 6. Seiridium. 

Conidia chains without isthmi 7. Seiridiella. 

Conidia ciliate 

Conidia ciliate at apex alone 

Conidia 1-cihate 8. Monochaetia, p. 558. 

Conidia several-ciliate 9. Pestalozzia, p. 558. 

Conidia 1-ciliate at each end 10. Hyaloceras. 

Toxosporium Vuillemin (p. 557) 

Acervuli sublenticular, erumpent, scattered, minute, black; 
conidia curved, beaked at each end, central cells dark, apical hya- 
line; conidiophores short, simple. 

T. abietinum Vuill.^^^ causes drying out of Abies leaves in 
Europe. 

Monochaetia Saccardo 

As in Pestalozzia except that the conidia bear only a single 
seta. About sixty species. 

M. pachyspora Bubak. is common on Castanea, causing large, 
circular, dead leaf spots with the acervuli showing in somewhat 
concentric circles. 

Pestalozzia de Notaris 

Acervuli subcutaneous, erumpent, discoid or pulvinate, black; 
conidia elongate, colored or the end cells hyaline, with several 
hyaline sette on each end. 

A genus of over two hundred species of various habit, some of 
considerable economic importance. 

P. hartigii Tub. causes disease of tree and shrub seedlings in 
nurseries, constricting the stem just above the soil and resulting 
in death. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



559 




Fig. 376. — P. funeioa. 
B. A young mycelium, 
of an older myceliuna. 



A. Spores. 

C. Hypha 

After Reed. 



P. funerea Desm. 

Acervuli scattered, punctiform, blackish, subepidermal, erum 

pent; stroma depressed, white; 

conidia oblong, fusoid, 5-celled, 

constricted at the septa, the three 

central cells fuscous, the others 

hyaline, 22-32 x 6-8 m, with 2-5 

recurved hyaline spines, 10-15 x 

0.7-1 fx; conidiophores short, 5-9 x 

1-1.5 tx. 
It is found on various conifers 

causing disease and is a common 

saprophyte. In America it causes 

a stem spot or anthracnose of ginseng,^"* girdling the petioles. 

The culture characters were studied by Reed.^^® 
P. guepini Desm. var. vaccinii Sh.^^'' 

Acervuli minute, punctiform, convex, black, subepidermal, 

erumpent; conidia el- 
liptic and somewhat 
unequilateral, about 
20 fx long; central cells 
dark, the two end cells 
hyaline, the apical cell 
with 3-4 filiform setae 
22-35 n long, the basal 
with a short hyaline 
appendage, 6-12 /x. 

Common on fallen 
leaves of cranberries, 
and associated with 
rot of the berries. It 

T. „_- D ^ , . ... is common on tea 

biG.S7t. — Pestalozzia guepini vaccinn; a, a eonidium 

having an apical appendage with three branches; CaUsing a SCrioUS dis- 
b, a conidium having an apical appendage with , ^ ,,. 

four branches; c, a germinating conidium; d, a ger- Case, alSO On Uamellia, 

minating conidium sending out two germ tubes, "^/ron^r^lir. /~* i + ^ n c. 

After Shear. IViagnolia, V^ 1 1 r U S, 

Rhododendron. 
P. uvicola Speg.^^^ 
Acervuli globose, lenticular, black, subepidermal, erumpent. 




560 THE FUNGI WHICH CAUSE PLANT DISEASE 

300-400 n; conidia fusiform, 5-celled, the three median oUvaceous- 
fuscous, the others hyahne, 35 x 8-10 fx, inferior appendage 25-30 
X 1 jjL, superior group 8-10 x 1 /x. 

It is described as the cause of rot of grape berries and of a leaf 
spot of the vine. 

P. aloea Trinch. occurs on aloe in Italy; 

P. clusiae Griff. & Mont, on Clusia leaves in France; 

P. richardiae Hals, sometimes disfigures calla leaves. 

P. tumefaciens Hen. is found on Abies causing galls. 

P. gongrogena Temme causes galls and cankers on willow; 

P. fuscescens Sor. parasitizes cultivated Corypha; 

P. fuscescens var. sacchari Wak. is on sugar cane. 

On palms occur P. palmicola S. & S., P. palmarum Cke., and 

P. phoenicis Grev. 

P. inquinans C. & Hark is on eucalyptus in California; 

P. stictica B. & C. on sycamore and linden; 

P. suffocata E. & E. and P. discosioides E. & E. on roses. 

P. lupini Sor. on Lupinus cotyledons. "°° 

Coryneum Nees. (p. 558) 

Acervuli discoid or pulvinate, subcutaneous, erumpent, black, 
compact; conidia oblong to fusoid. 

Some seventy-five species. 

C. modonia (Sacc.) Griff. & Maub. on chestnut=Melanconis 
modonia Tul. See p. 281. 

C. juniperinum E. on juniper =Exosporium juniperinum.^"^ 

C. beyerinckii Oud. 

Acervuli minute, punctiform, black, gregarious; conidia borne 
on a parenchymatous pulvinate stroma, stipitate, oblong, ovate, 
light olivaceous, 3 to many-septate, slightly constricted at the 
septa or not, cells not all of the same size. 

Ascospora beyerinckii is said by Vuillemin to be the ascigerous 
stage. See p. 236. It is reported as injurious to peaches, caus- 
ing blight and shot-hole in California ^°^ and to apricots, cherries 
and peaches in Africa. It is close to and perhaps identical with 
Clasterosporium carpophilum. 

The acervuli occur as black specks near the centers of the leaf 



THE FUNGI WHICH CAUSE PLANT DISEASE 561 

spots but since diseased tissue soon drops out they are often diffi- 
cult to find. Bark spots are often sterile. Late in the season spores 
abound scattered on the surfaces of twigs, especially at rough 
places, as near leaf scars. Spores near bud scales penetrate them 
with a mycelium and kill the buds or if on bark they enter the 
twig and produce dead spots. 

C. foliicolum Fuckel.-«=^ 

Spots epiphyllous, ochraceous, indefinite; acervuli punctiform, 
erumpent; conidia ellipsoid-oblong, 17 x G-7 n, 3-septate, con- 




FiG. 378. — C. beijerinckii. Longitudinal section of a pustule. 
After Smith. 

stricted at the septa, olivaceous, lower cell subhyaline, stalk 
subhyaline, 15-20 x 1.25 fi. 

It is present as a saprophyte on apple leaf spots and causes 
cankers on twigs and branches. 

C. camellias Mas. is reported on cultivated Camellia. 

C. mori Namura causes mulberry twig blight in India. ^°^ 

The Melanconiaceae-Hyalodictyae and Melanconiaceae-Phseod- 
ictyae containing only three genera have no parasitic species of 
importance. 

Melanconiaceae-Scolecosporae (p. 537) 

Conidia cylindric, filiform or suballantoid, hyaline, mostly con- 
tinuous. 



562 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Key to Genera of Melanconiaceae-Scolecosporae 

Conidia allantoid 1. Naemospora. 

Conidia bacillar to filiform 

Conidia fasciculate at the apex of the 

conidiophores 2. Trichodytes. 

Conidia solitary- 
Masses white or pale, foliicolous; conidia 

filiform 3. Cylindrosporium,p. 562. 

Masses gray or dark, usually ramicolc; 

conidia falcate 4. Cryptosporium, p, 564. 

Masses bright-colored, saprophytic; 

conidia falcate 5. Libertella, p. 564. 



Cylindrosporium Unger 

Acervuli subepidermal, white or pallid, disciform or siibeffuse; 
conidia filiform, continuous, hyaline, straight or curved. 

About one hundred species of 
parasites, several of them of con- 
siderable economic importance. 

C. mori Berl. on Morus=Myco- 
sphserella morifolia. See p. 249. 

C. castanicolum (Desm.) Berl. 
on Castanea=Mycosphserella macu- 
liformis. See p. 249. 
C. padi Kavst:-"'"--''^ 
Hypophyllous; spots angular, sub- 
fuscous; acervuli subepidermal caus- 
ing elevations; conidia curved, 
cylindric, 48-60 \ 2 fx; conidio- 
phores minute, produced in great abundance. 

This is the cause of the most common, familiar, widespread and 
destructive shot-hole disease of the cherry and plum. When on 
the peduncles the fruits are dwarfed and ripen unevenly. The 
diseased leaf tissue usually falls away, resulting in "shot-holes." 
Acervuli abound. 

Arthur found a Phoma associated with this fungus and later 
asci in the same pycnidia. He believed these forms all con- 




FiG. 379. — C. padi, section of acer- 
vulus. After Pammel. 




THE FUNGI WHICH CAUSE PLANT DISEASE 563 

nected but confirmation of such conclusion has not been ad- 
duced. Connection with Coccomyces has also been reported. ^^^ 

C. tubeufiana All., also on Prunus is closely like C. padi. 

C. pomi Brooks.211-212 

Acervuli pallid, subeffuse, at first subepidermal, then erumpent; 
conidia granular, filiform, straight or 
flexuose, 15-80 x 2-2.5 /x. 

It is reported as common from 
New Hampshire to Virginia and Michi- 
gan on apples of almost all varieties, 
causing small, dry, sunken, brown fruit 
spots; a disease which had hitherto 
been referred to a variety of causes. 
The fungus was studied in numerous pi^. 380.— Cyiindrosporium 
culture media and its pathogenicity was Sdaf ^'"uTtures.™'' iTt ^ r 
proved by inoculations. Brooks. 

C. chrysanthemi E. & D.^^ 

Spots subindefinite, 1 cm. or more broad, black; acervuli innate, 
amphigenous, 100-170 n; conidia fusoid straight, 50-100 x 3-4. 5;u. 

The fungus causes dark blotches on the leaves of chrysanthemum. 

C. clematidis E. & E. 

Spots amphigenous, reddish-brown, round or subangular, 1-3 jx; 
acervuli comparatively few, epiphyllous, immersed, scattered; co- 
nidia fusoid-linear, 75-80 x 2.5-3 ix, somewhat curved, exuding in a 
white mass. It causes leaf spot of Clematis. ^^ Later is described 
a variety jackmanii which differs from the species in the acervuli 
not being confined to the spots, which are less definite, and exud- 
ing a black mass of spores which are themselves hyaline. 

C. humuli E. & E. 

Spots amphigenous, mostly hypophyllous, small, angular, limited 
by the veinlets, rusty brown; acervuli minute, black, amphigenous; 
fconidia nearly cylindric, granular, 40-50 x 3 m, oozing out in a 
white mass. 

The cause of leaf spots of hops.^^ 

Other parasitic forms are : 

C. saccharinum E. & E. on maple; 

C. colchici Sacc. on Colchicum; 

C. inconspicuum Wint. on lily; 



564 THE FUNGI WHICH CAUSE PLANT DISEASE 

C. orni (Pass.) Pegl. and 

C. viridis E. & E. on ash; 

C. quercus Sor. on oak; 

C. cercosporoides E. & E. on tulip tree. 

An unidentified Cylindrosporium is reported from New Jersey 
and New York as causing spots of tomato with considerable in- 
jury. 

It is possible that this was in reality Septoria lycopersici.^^' ^''° 

Cryptosporium Kunze (p. 562) 

Acervuli discoid-conic, covered by a peridium, erumpent, form- 
ing a pseudo-pycnidium from the substratum; conidia fusoid- 
falcate, large, continuous, typically stipitate. 

Some forty species, chiefly saprophytes. 

C. leptostromiforme Kiihn forms black stromata on lupine. 

C. minimum Lau. is the cause of a rose stem disease and of 
cankers. 

Libertella Desmaziere (p. 562) 

Acervuli covered, irregularly and tardily erumpent, conidia 
filiform, falcate, elongate, continuous. 

Some twenty species, chiefly saprophytes. 

L. rubra Bon. on Prunus =Polystigma rubrum. See p. 208. 

L. ulcerata Mas. causes cankers on fig trees in greenhouses.^^* 

Moniliales (p. 479) 

The Moniliales differ from the Sphseropsidales in the ab- 
sence of the pycnidium and from the IVIelanconiales in their 
somewhat loose, separate hyphce, not innate and closely aggregated 
as in the Melanconiales. There are genera on the boundaries 
between these orders which are difficult to place, as for example 
Coryneum, some species of which are often put in Helmin- 
thosporium; Vermicularia which sometimes is confounded with 
Volutella, etc. 

The order is one of very great diversity and contains a multitude 
of forms. Many are only saprophytes while some are aggressive 
parasites. 



THE FUNGI WHICH CAUSE PLANT DISEASE 565 



Key to Families of Moniliales 

Hyphae in more or less loose cottony 
masses 
HyphsD and conidia clear or bright 

colored I. Moniliaceae, p. 565. 

Hyphse and conidia typically both dark; 

one or the other always dark II. Dematiaceae, p. 594. 

Hyphse compactly united or forming a 

globose to cylindric body which is 

often stalked 

Hyphal body cylindric to capitate, 

stalked, i. e., a synnema or cory- 

mium III. Stilbaceae, p. 632. 

Hyphal body more or less globose, 

sessile, i. e., a sporodochium IV. Tuberculariaceae, p. 638. 

Moniliaceae 

Hypha3 hyaline or bright colored, more or less fragile, lax, not 
cohering in fascicles; conidia concolorous, hyaline or bright colored. 

Key to Sections of Moniliaceae 

Conidia globose, ovate, oblong or short- 
cylindric 

Conidia continous 1. Amerosporae, p. 565. 

Conidia two-celled 2. Didymosporae, p. 585. 

Conidia three or more-celled 3. Phragmosporae, p. 588. 

Conidia muriform 4. Dictyosporae, p. 592. 

Conidia cylindric, spiral or convolute, 

usually septate 5. Helicosporae. 

Conidia of several stellately grouped cells. . 6. Staurosporae, p. 593. 

Moniliaceae-Amerosporae 

Conidia continuous, globose or ovoid to short cylindric. 

Key to Groups of Moniliaceae-Amerosporae 
Hyphae very short, or obsolete, little dif- 
ferent from the conidia 

Conidia not in chains 1. Chromosporieae, p. 566. 

Conidia in chains 2. Oosporeae, p. 567. 



566 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Hyphse elongate and distinct from the 
conidia 
Conidiophores simple or little branched, 
apically swollen 

Conidia solitary 3. Hartigielleae, p. 570. 

Conidia in heads 

Conidia not in chains 4. Cephalosporieae, p. 570. 

Conidia in chains 5. Aspergilleae, p. 572. 

Conidiophores much-branched, conidia 
not in heads 
Conidia borne irregularly on simple 
or branched but not inflated or 

verticillate conidiophores 6. Botrytideae, p. 574. . 

Conidia borne on verticillately 

branched conidiophores 7. Verticilliae, p. 583. 

Conidiophores with inflated nodes upon 

which clusters of conidia are borne 8. Gonatobotrytideae. 



Chromosporieae (p. 565) 
HyphsB short or obsolete, conidia not in chains. 



Key to Genera of Chromosporieae 

Conidia solitary, at least not capitate 
Saprophytic 

Hyphse almost none 

Conidia separate 1. Chromosporium. 

Conidia joined in twos or threes, 

not catenulate 2. Selenotila. 

Hyphse very short, branched, septate 3. Coccospora. 

Entomogenous 4. Massosporao 

Phytogenous 
In fungi 

Conidia ovoid, smooth 5. Myceliophthora, p. 567. 

Conidia globose, verrucose 6. Coccosporella. 

In leaves, hyphse vermiform-tortuous 7. Ophiocladium, p. 567. 
Conidia capitate; hyphse lacking; biophil- 

ous 8. Glomerularia. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



567 



Myceliophthora Costant (p. 566) 

Sterile hyphse creeping, simple or somewhat branched, bearing 
conidia at the apex; conidia solitary, 
acrogenous, ovoid. ^■^^m^^(^ 

A single species M. lutea Costant. ^^^^^^o 

causes disease of cultivated mush- ^^IwM-^ 

rooms in France. ^^^ ■ — \f — \(W^i^4^§^^ , — ir- 

Ophiocladium Cavara (p. 566) ^vOU^^^-v^^'^ 

Fertile hyphse fasciculate, tor- ^ '\< \C»~\\ V a( 

tuose; COnidk acrogenous, ellip- Fig.381.— O. hordeiaccrvulusand 
' o 7 r- spores. After Cavara. 

tic. 

Two species of which one, O. hordei Cav., parasitizes barley. 

Oosporeae (p. 565) 
Hyphffi short or obsolete, conidia in chains. 

Key to Genera of Oosporeae 

Conidial chains arising in the hyphse 

Conidial branches simple, arcuate 1. Malbranchea. 

Conidial branches dichotomous, not 

arcuate 2. Glycophila. 

Conidial chains arising at the apex of the 

hyphse 
. Conidia globose, elliptic, or ovate 
Conidia all of equal size 

Sterile hyphse very short or none. . . 3. OSspora, p. 568. 
Sterile hyphse evident, rarely none 
Conidia not connected by an 
isthmus 
Growing within the substratum 

Haustoria none 4. Monilia, p. 568. 

Haustoria present 5. Oidiopsis. 

Growing on the surface of living 

plants 6. Oidium, p. 569. 

Conidia connected by an isthmus . 7. Paepalopsis. 

Apical conidium larger 8. Halobyssus. 

Conidia fusoid, acute at each end 9. Fusidium, p. 568. 



568 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Conidia cylindric or cuboid 

Hyphse nearly obsolete; conidia cylin- 
dric 10. Cylindrium. 

Hyphse distinctly present 

Conidia cylindric. 11. Polyscytalum. 

Conidia cuboid 12. Geotrichum. 




Oospora Wallroth (p. 567) 

Fertile hyphse short, sparingly branched, 
slender; conidia catenulate, globose to ovoid, 
hyaline or dilute-colored. 

Over one hundred species, chiefly saprophytes. 

O. scabies Thax.^i". 217. 219-224 

Vegetative hyphse rarely 1 n thick, curved ir- 
regularly, septate or falsely septate, branching; 
aerial hyphse at first white, then grayish, 
evanescent, breaking up into bacteria-like 
spores. 

Isolation and inoculation in pure culture by 
Thaxter showed this to be the cause of the 
Fig. 382 — uospora. common American form of scab of Irish potato, 

After Baccardo. 

beet, turnip, etc. 
O. abietum Oud. causes defoliation of firs in Europe.^^^ 

Fusidium Link (p. 567) 

Hyphse short, simple, not well differentiated from the conidia 
which are fusoid, catenulate, acute at the ends, hyaline or dilute- 
colored. In part =Nectria. See p. 201. 

A poorlj'' understood genus of over 50 species. 

F. candidum Link, on various trees=Nectria ditissima. See 
p. 203. 

Monilia Persoon (p. 567) 

Hyphse erect, branched, forming a dense mycelial felt, which 
produces numerous conidiophores; conidia catenulate, hyaline or 
light-colored, ovate or lemon shaped. In part=Sclerotima. See 
p. 136. 

Some fifty species. 



THE FUNGI WHICH CAUSE PLANT DISEASE 569 

M. fructigena Pcrs. on stone and pome fruits =Sclero.tinia 
fructigena. See p. 139. 

M. cinerea Bon. on stone and pome fruits =Sclerotinia cinerea. 
See p. 137. 

M. cinerea Bon. on Prunus padus=Sclerotinia padi. See p. 140. 

M. cinerea Bon. on Vaccinium oxycoccus=Sclerotinia oxycocci. 
See p. 140. 

M. laxa A. & R. on apricots =Sclerotinia laxa. See p. 137. 

M. linhartiana Sacc. on medlars and quinces ^^=Sclerotinia 
linhartiana. See p. 141. 

M. crategi Diedicke on Crataegus =Sclerotinia crategi. See 
p. 143. 

M. seaveri Reade on Prunus =Sclerotiiiia seaveri.^^^' ^^^ See 
p. 140. 

M. fimicola Cast. & Matr. is a parasite of mushrooms, Clitocybe 
and Pleurotus. 

Oidium Link (p. 567) 

On the surface of Hving leaves; hj^phse branched, white, bearing 
erect, simple conidiophores with catenulate, ovoid conidia. 

About fifty species. 

These conidial fungi in the main belong to the Erysiphales 
though some forms are placed in Oidium which clearly do not 
belong to that ascigerous order. Salmon states that there are 
some forty-four apparently Erysiphaceous Oidiums listed; but 
that twenty-five of these grow on plants known to be the hosts 
of ascus bearing Erysiphacese. 

O. fragariae Harz.=S. humuli. See p. 175. 

O. leucoconium Desm.=S. pannosa. See p. 176. 

O. balsamii Mont.=E. polygoni. See p. 177. 

O. ambrosise ThUm.=E. cichoracearum. See p. 178. 

O. monilioides Link.=E. graminis. See p. 179. 

O. tuckeriBerk.=U. necator. See p. 181. 

O. crataegi Grogn.=P. oxyacanthse. See p. 183. 

O. farinosum Cke.=P. leucotricha. See p. 184. 

The following may also be mentioned : 

O. erysiphoides Fr. on hop, clover, cucumber, etc.; 

O. chrysanthemi Rab. on chrysanthemums; 



570 THE FUNGI WHICH CAUSE PLANT DISEASE 

O. mespilinum Thiim on Mespilus; 

O. tabaci Thiim on tobacco; 

O. verbenas T. & B. on Verbenas. 

O. quercinum Thiim has been reported as the cause of much 
injury to oaks in Europe since 1907. The identity of the Oidium 
causing the epidemic is, however, much questioned. By some it is 
regarded as a stage of Microsphsera alni, by others it is set up 
under a separate name as O. alphitoides G. & M.^^^' ^'® 

Hartigielleae (p. 566) 

One genus, Hartigiella Sydow. The species H. laricis (Hart.) 

Syd. causes fall of needles of larch. 

Cephalosporieae (p. 566) 
Hyphae elongate; conidia in heads. 

Key to Genera of Cephalosporieae 

Conidia globose or oblong 

Conidia sessile on the head or nearly so 
Fertile hyphse inflated at apex 
Apical vesicle globose-inflated 

Conidia sessile, not mucus-covered 
Vesicle verrucose or muriculate 

Fertile hyphee simple 1. CEdocephalum. 

Fertile hyphse sigmoid, much 

branched 2. Sigmoideomyces. 

Vesicle hexagonally areolate. ... 3. Rhopalomyces. 
Conidia on stalks, mucus-covered . 4. Gliocephalus. 
Apical vesicle clavate or lobed 
Vesicle disk-shaped, stellate- 

lobed 5. Coronella. 

Vesicle clavate or subpalmate. ... 6. Buseella. 
Fertile hyphse not inflated at apex 
Conidial head covered with mucus 

Fertile hyphse simple 7. Hyalopus. 

Fertile hyphse with verticillate 

branches at tip 8. Gliobotrys. 

Conidial head without mucus 
Fertile hyphse with one head 
Conidia not separating 9. Papulospora. 



THE FUNGI WHICH CAUSE PLANT DISEASE 571 

Conidia separating 

Head elongate 10. Doratomyces. 

Head globose or slightly clavate 

Sterile hyphse scanty 11. Haplotrichum. 

Sterile hyphse long, decum- 
bent 12. Cephalosporium, p. 571. 

Fertile hyphse with 2 to several heads 
Conidia upright on verticillate 

conidiophores 13. Ccemansiella. 

Conidia in more definite heads 
Fertile hyphse simple, with 3 to 
several heads of conidia on 

spines 14. Botryosporium, p. 571. 

Fertile hyphse several times 2 to 

3-fid 15. Trichoderma. 

Conidia borne on little stalks or sterig- 
mata 

Fertile hyphse simple 16. Corethropsis. 

Fertile hyphse verticillate branched . . 17. Spicularia. 
Conidia short cylindric 

Conidia without mucus 18. Cylindrocephalum. 

Conidia covered with mucus 19. Acontium. 

Cephalosporium Corda 

Hyphse creeping, conidiophores short, erect, not apically swollen. 
Conidia spherical or ovate, hyaline or slightly colored. 

The small spored condial forms often associated with Fusarium 
(microconidia) belong to this form-genus. 

Botryosporium Corda 

Hyphse assurgent, simple or forked, elongate, irregularly later- 
ally branched; fertile branches simple, with three or more short 
apical branches which end in heads of conidia; conidia globose to 
ovate. 

A genus of only about ten species. 

B. diffusum (Grev.) Cda. has been reported as parasitic on Cas- 
uarina; 

B. pulchrum Cda. on wheat and radish. 

B. longibrachiatum (Oud.) Maire on various green-house plants. 



572 THE FUNGI WHICH CAUSE PLANT DISEASE 

Aspergilleae (p. 566) 
Hyphae well developed; conidia in heads, catenulate. 

Key to Genera of Aspergilleae 

Fertile hyphse inflated at apex 
Fertile hyphse simple or nearly so 

Sterigmata of apical vesicle none or 
simple 

Conidia terminal on sterigmata 1. Aspergillus, p. 572. 

Conidia lateral and terminal on ster- 
igmata 2. Dimargaris. 

Sterigmata verticillately branched. ... 3. Sterigmatocystis, p. 573, 
Fertile hyphse dichotomous, branches 

curved 4. Dispira. 

Fertile hyphse little or not at all inflated 
Fertile hyphse verticillately branched at 
tip 
Tips equally verticillate; conidia doli- 

form 5. Amblyosporium. 

Tips unequally verticillate; conidia 
globoid 
Conidia without mucus 

Conidiophores slender 6. Penicillium, p. 573. 

Conidiophores swollen, conidia en- 
closed in mucus 7. Gliodcladium, p. 574. 

Fertile hyphse not verticillate at tip 8. Briarea. 

Aspergillus (Micheli) Link 

Hyphse effused, creeping; conidiophores erect, simple, capitate; 
conidia catenulate; sterigmata none or indistinguishable from the 
conidia. 

The conidia are often found, the asci but rarely. 

A. fumigatus Brizi, is held responsible by Brizi^^'' for pathological 
changes in wheat seed which rendered them incapable of germina- 
tion. 

A. ficuum (Hen.) Weh. and A. phoenicis (Cda.) Lind. occur on 
figs. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



573 



Sterigmatocystis Cramer (p. 572) 

As in Aspergillus but with the sterigmata branched in whorls 
at the apex. 

S. niger Van Tiegh. 

Hyphse slender, conidiophores erect, 800-1000 x 11-16 n, thick- 
walled, hyaline or dark above, the apical globose swelling black; 
basidia 40 n long, radiately arranged, sterigmata obclavate, 8- 





FiG. 3S3. 



-B. pulchrum. After 
Corda. 



Fig. 384. — Aspergil- 
lus. From Strass- 
burger et al., Text 
Book of Botany. 



10 fi long; conidia globose, 3.4-4.5 n, minutely verrucose, violet- 
brown, catenulate. On tobacco. 

S. ficuum (Reich.) Hen. 

Conidia globose, 3.8 n, dark violet, thick-walled, smooth. 

In the fruits of figs in Asia Minor and United States. 

S. luteo-nigra Lutz. is injurious to cacao in the tropics. 



Penicillium Link (p. 572) 

Hyphse creeping; conidiophores erect, apicallj' irregularly ver- 
ticillate-penicillately branched; conidia catenulate, spherical, or 




574 THE FUNGI WHICH CAUSE PLANT DISEASE 

elliptical, hyaline or variously colored. For the ascigerous stage 

see page 167. 

The conidial stages of many Penicilliums have been given 

searching investigation and comparative study by Thom.^^^ 

P. glaucum Lk. 

Hyphffi effused, creeping, septate, interwoven, white, conidio- 

phores penicillate, branches single or in pairs, erect, forked; conidia 

globose to broadly elliptic, smooth, hyaline, 

with a tinge of green, 4 fx. 

It is the cause of rot of ripe oranges, lemons, 

apples, etc. 

P. italicum Weh. is described as a wound 

parasite on oranges by Massee. It is very 

similar in appearance to P. glaucum but a 

Fig. 385.— Penicillium. little greener; conidia elliptic-oblong, 7-9 x 4 /x. 
After Bref eld. t» j- -4. j. /t^ \ o 

P. digitatum (Fr.) Sacc. 

Similar to the preceding species in habit but the conidia are 
white in mass, 4-6 fx. Often associated with, and similar in effects 
to P. glaucum. 

P. olivaceum Weh. is found on citrous fruits; 

P. luteum Zuk. on apple. 

An undetermined species is reported as the cause of a white dry 
rot of sweet potatoes. ^^° 

Various other species of the genus occur on fruits and vegetables 
causing their decay. 

Gliocladium Corda (p. 572) 

Hyphae effused, spreading; conidiophores and conidia as in 
Penicillium but the conidia surrounded Vjy a mass of mucus. 

A genus of only about ten species. 

G agaricinum C. &. M. arrests growth and breaks the pilei of 
mushrooms. 

Botrytideae (p. 566) 

Conidiophores elongate, simple or branched but not inflated, 
and the branches not verticillate; conidia borne variously, globose 
or ovate to elliptic. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



575 



Key to Genera of Botrytideae 

Conidia smooth or scarcely roughened 
Saprophytic or apparently so, often real 
parasites 
Conidia typically pleurogynous 
Fertile hyphae 2 to several-furcate. . . 1 . Haplaria. 
Fertile hypha) simple or nearly so 

Conidia globose or ellipsoid 2. Acladium. 

Conidia short cylindric 3. Cylindrotrichum. 

Conidia acrogenous or pleurogynous 
Some intermediate joints of the hy- 
phiB swollen and denticulate, 

conidia-bearing 4. Physospora. 

Intermediate joints equal 

Conidia-bearing hypha) of two sorts, 

the upright alone denticulate 5. Blastomyces. 

Conidia-bearing hyphse of one sort 

Fertile hyphse simple or nearly so 

Hyphffi not denticulate; 

conidia solitary 

Hyphse forming a crust-like 

stratum 6. Hyphoderma. 

Hyphse loose, cobwebby. . . 7. Acremonium, p. 577. 
Hyphse denticulate ; conidia 
usually grouped 
Hyphse everywhere denti- 
culate, bearing conidia 

only at tip 8. Xenopus. 

Hyphse denticulate or pro- 
liferous at tip alone 
Apex denticulate, many- 

spored 9. Rhinotrichum. 

Apex inflated-ampuUi- 

form, 1-spored 10. Olpitrichum 

Fertile hyphse branched 
Conidia globose to ovoid 
Both sterile and fertile 
hyphse procumbent 
Sterile hyphse intracellu- 
lar 11. Hartigiella. 



576 THE FUNGI WHICH CAUSE PLANT DISEASE 

Sterile hyphse superficial 
Fertile hyphse vaguely 
branched 
Conidia acro-pleuro- 

gynous 12. Sporotrichum, p. 577. 

Conidia on a one- 
sided synipo- 

dium 13. Monopodium. 

Fertile hyphaj dichoto- 
mous; conidia ac- 
rogenous on spine- 
like branches 14. Langloisula. 

Fertile hyphse eriect or as- 
cending 
Conidia solitary acrogen- 
ous 
Fertile hyphse spiny- 
branched at apex. 15. Plectothriz. 
Fertile hyphse not 

spiny-branched. . . 16. Monosporium. 
Conidia loosely grouped 
about the apex 
Conidia not involved 
in mucus 
Conidia on inflated 

muriculate apices 17. Phymatotrichum. 
Apices not muricu- 
late or inflated. 18. Botrytis, p. 578. 
Conidia involved in 

mucus 19. Tolypomyria. 

Conidia fusoid to cylindric 
Fertile hyphse mostly pro- 
cumbent 20. Sporotrichella. 

Fertile hyphse erect or as- 
cending 
Conidia fusoid on the 
upper side of curved 

branches 21. Martensella. 

Conida acrogenous 
Conidia-bearing 

branches terete. . . 22. Cylindrophora. 



THE FUNGI WHICH CAUSE PLANT DISEASE 577 

Conidia-bcaring 

branches ellipsoid 23. Cylindrodendrum. 
Biogenous 

Conidia smooth 

Cateuulate 24. Ovularia, p. 582. 

Solitary 25. Ovulariopsis, p. 582. 

Conidia densely spiny 26. Ramulaspera. 

Conidia muricate or tuberculose-stellate 
Conidia globose 
Conidia merely muricate 

Hyphse loose, cobwebby 27. Sepedonium. 

Hyphse woven into a subgelatinous 

pellicle 28. Pellicularia, p. 382. 

Conidia setose at apex as well as muri- 
cate 29. Chaetoconidium. 

Conidia tuberculose-stellate 30. Asterophora. 

Acremonium Link (p. 575) 

Hyphae subsimple, procumbent; conidiophores simple, short; 
conidia solitary, hyaline or light colored, 
oval to ellipsoid. 

A genus of some ten species. 

An undetermined species is recorded by _ 
Humphrey -''• ^-^ as causing disease of cucum- '^f/p'l 
bers in IVIassachusetts. I' \i 

Sporotrichum Link (p. 576) 

Fig. 386. — Acremonium. 

Hyphse widely spreading, much branched; After Saccardo. 
conidiophores simple, short; conidia solitary or in groups on 
separate sterigmata, ovoid or subglobose. 

Over one hundred twenty-five species are described, most of 
which are saprophytes. 

S. pose Pk. 

Hyphee creeping, interwoven, branched, continuous or sparingly 
septate, variable in thickness, 2.5-6 n, hyaline, forming a loose 
cottony stratum; conidia of two kinds; microconidia, globose or 
broadly ovate, 4-12 /x; macroconidia abundant, elongate elliptic to 
ovate elliptic, 1 rarely 2-septate, about three or four times as 
large as the microconidia. 





578 THE FUNGI WHICH CAUSE PLANT DISEASE 

The form is an atypical one in 
that it produces two kinds of 
spores; one kind which is usually 
septate 

Heald ^-^ also Stewart and Hodg- 
kiss ^^"^ have described it as the 
cause of bud rot of carnations, while 
the latter authors also mention it 
in connection with a disease known 
as "silver top" of June grass in 
Fig. 3S7.--S. pojE. 11. Hyphabear- which the paiiicles wither as they 

ing conidiophores and macroco- * *' 

nidia. 13, Hypha bearing co- expand, tliough the autliors express 

nidiophores and microconidia. , , , , • , , i i i , • 

After Heald. doubt as to its actual causal relation 

to the disease. A mite appears to 
be the carrier of the spores. Cultural studies and cross-inoculation 
showed the fungus form on the two hosts to be identical. 

Botrytis (Micheli) Link (p. 576) 

Hyphse creeping; conidiophores simple or more or less markedly 
dendritic branched, erect, branches various, thin and apically 
pointed, thick and obtuse or cristate; conidia variously grouped 
at the apex of the branches, never in true heads, continuous, 
globose, elliptic or oblong, hyaline or light colored. 

In part =Sclerotinia. See p. 136. 

A genus of some two hundred or more species, several of them 
of great economic importance. 

This form-genus contains manj'^ parasites on various hosts. 
In some instances they are known to include ascigerous stages, 
(Sclerotinia), in their life cycle; in others no such relation is known, 
though it has often been assumed on quite untenable grounds. 
Specific limitations are but poorly understood and the relations 
between the various forms and between these forms and the as- 
cigerous stages are in a state of much confusion c. f. (p. 137). In 
some instances the same conidial stage is claimed by different in- 
vestigators as belonging to two distinct ascigerous species, a 
manifest impossibility, (e. g., S. fuckeliana and S. libertiana with 
B. cinerea.) „ - 



THE FUNGI WHICH CAUSE PLANT DISEASE 



579 



The more prominent forms as described are given below, recog- 
nizing that some of them may be co-specific. 

T, • r> 231-243 

B. cinerea Pers. 

Hyphae slender, constricted at septa, gregarious, simple or 
sparsely branched, erect, cinereous, conidia globose, pale. 

A form which occurs on the grape is usually referred to 
S. fuckeliana though there is not entire agreement on this point. 
On the grape the Botrytis develops its mycelium in the berries 
and produces dense tufts of conidia over their surfaces. The 
sclerotia form within the fruits. Leaves and 
canes are also affected, (see p. 140). 

On the lily Ward^^^ in a classic study de- 
monstrated the parasitism of the fungus show- 
ing its action to be dependent upon toxins and 
enzymes. The type in this case deviated some- 
what from the usual B. cinerea in that its 
spores were a little larger than is usual, but it 
nevertheless seemed to be this species. No 
ascigerous stage was found. 

On Cyclamen and Primula Wehmer^^^ re- 
ports a similar case.-^° The fungus has also 
often been reported on the cultivated gera- Fig. 388.— b. cinerea. 

^ After Smith. 

nium. 

On lettuce Humphrey, -^^ Jones, ^^^ Bailey,^^' and many others 
have reported a greyish mold on the leaves due to a Botrytis 
which is often cited as B. cinerea though it appears to form no 
ascigerous stage. The affected part of the leaf collapses and is 
covered with a conspicuous growth of the conidiophores and coni- 
dia. Small sclerotia are produced in considerable abundance 
when on artificial media but they, on germination, bear clusters, 
dense bushy tufts, of conidiophores. That this form on lettuce 
ever produces ascophores is doubtful. 

Smith describes a case in which linden stems beginning at the 
ground were parasitized by B. cinerea. The bark appeared to be 
first affected and sclerotia formed in the cortical parenchyma. 
Similar cases are on record regarding the rose, various conifers, 
grape (Brizi) Aesculus, Prunus. In all of these cases the Botrytis 
seems to be B. cinerea and without ascophores. 




580 THE FUNGI WHICH CAUSE PLANT DISEASE 

Numerous studies ^^^ of the power of B. cinerea to infect growing 
tissue have been made with the conclusion that it is a weak parasite 
and that to become aggressively parasitic it must first develop 
a vigorous mycelium saprophytically. Attempts to immunize 
plants against its attack have been made with partial suc- 
cess.^*^ 

Extensive studies of the condition of sclerotia and conidia forma- 
tion by B. cinerea (from grape) were made by Reidemeister.^^^ 
He concludes that sclerotia form on all media favorable to growth 
of the fungus. They are on an average 5-8 mm. in diameter, 
smaller under conditions of poor nutriment, high osmotic pressure 
or strong transpiration. The}'' are often found in concentric rings 
and their formation is induced by the presence of various agents 
which inhibit groAvth. Conidia are formed under condition of 
energetic transpiration and on media of high osmotic tension. 
Conidia and sclerotia vary inversely in production. Appressoria 
develop on all media where sclerotia grow and are favored by 
substances which inhibit growth. Conidia are suppressed by 
conditions favoring the formation of appressoria. 

B. depraedens Cke. is a pest of the sycamore. 

B. fascicularis (Cda.) Sacc.^^ 

Cespitose, minute, brownish; hyphae erect, fasciculate, flexuose, 
brown, or semi-pellucid, branches hyaline; conidia in subglobose, 
white heads, oblong, large. 

A mold of egg-plants is attributed to this fungus by Hal- 
sted. 

An undetermined Botryiis is reported on carnation by Atkinson 
and another on Ribes.^^* 

B. parasitica Cav. 

Hyphse cinereous, sparse, erect, inflated at base; conidia ovate, 
large, short-pedicillate, on short branches, heads umbellate, hya- 
line or dilute, cinereous, 16-20 x 10-13 n. 

This is said by Halsted ^Ho be the form found on lilies, parti- 
cularly the bulbs, in New Jersey. It was first reported by Cavara 
in Italy and is widespread and destructive. 

B. poeoniae Oud. 23. 245. 246 

Mycelium in the parenchyma of the host, hyphse erect, 0.25- 
1 mm. high, protruding through the stomata, branches spirally 



THE FUNGI WHICH CAUSE PLANT DISEASE 581 

arranged, simple, or branched; conidia, numerous, in heads 12-15 
H across, oblong or ovate-oblong, 16-18 x 7-7.5 /x, hyaline or di- 
lute colored. 

It is reported as the cause of considerable injury to peonies in 
different parts of the United States. The greenish-black flat 
sclerotia are found inside the stems. 

It is mentioned by Bos -^^ as parasitic on young peony stems and 
on lily-of-the-valley and lilac. 

B. longibrachiata Oud.222. 248 

White, sparse, cespitose, 1.5-2 mm. high; mycelium creeping, 
branched; fertile hyphse, verticillate, hyaline, much branched 
and apically inflated; conidia numerous, hyaline, oval, 4.5-5.5 x 
2.5/1. 

It was reported by Thaxter ^-" as the cause of stem rot of to- 
bacco in the curing house. The affected stems are covered with 
white velvety patches of mycelium which soon spread to the 
veins. 

The same fungus is reported by Aderhold on ferns. ^'^^ 

This is perhaps a form of B. cinerea. 

B. douglassi Tub. on fir may be B. cinerea and=Sclerotinia 
fuckeliana. See p. 140. 

B. citricola Brizi, closely related to B. cinerea, attacks oranges 
and citrus fruits resulting in mummies. 

B. diospiri Brizi attacks the persimmon fruit near time of ripen- 
ing and prevents maturity. 

B. patula S. & Ber.^^" 

Cespitose, minute, greyish- white, spots cottony, suborbicular; 
fertile hyphse assurgent, continuous, filiform, branching, panicu- 
late; conidia large, globose or globose-elliptic. 30 /i in diameter, 
light yellow. On raspberries. 

B. infestans (Hazsl.) Sacc. is common on hemp in Europe. It 
sometimes is associated with Sclerotinia libertiana which has led 
some to assume its connection with that fungus; but no such 
genetic relation is probable. 

B. galanthina Lud. occurs on snowdrops. It is said to belong to 
Sclerotinia galanthina, see p. 141, but the asci have not been seen. 

Undetermined species are reported on carnations, Ribes and 
mangold. 2^^ 




582 THE FUNGI WHICH CAUSE PLANT DISEASE 



Ovularia Saccardo (p. 577) 

Hyphse, simple, or sparingly branched, erect, apically simple 
or dendritically branched; conidia globose or 
ovoid, solitary, rarely in short chains. 
Over seventy-five species, all parasites. 
O. necans (Pass.) Sacc. produces spots on 
quince leaves in Italy and France; 

O. canaegricola Hen. on economic species of 

Fig. 389.— Ovularia. Rumex ; 

After Sorakin. Q. armoraclae Fcl. on horseradish; 

O. interstitialis B. & Br. and O. primulana Thiim. on primrose 
leaves; 

O. vicias (Frank.) Sacc. on Vicia; 

O. corcellensis Sacc. on Primula; 

O. alnicola Cke. on Alnus; 

O. rosea Fcl. on willow; 

O. villiana Mag. on lemons; 

O. syringae Berk, on lilac. 

O. citri B. & F. causes the white rust of lemons in Sicily.^^'^ 

A lemon disease in Australia has been credited by McAlpine ^^^ 
to O. citri McAlpine. 

O. medicaginis Br. & Cav. is on alfalfa; 

O. exigua (W. Sm.) Sacc. on clover. 

Ovulariopsis Patouillard & Hariot (p. 577) 

Similar to Ovularia, except in the solitary, acrogenous, sub- 
clavate conidia. 

Sterile hypha creeping, conidiophores erect, simple, septate, at 
apex with a single 1-celled hyaline, subclavate conidium. 

A small genus of leaf parasites, in part conidia of the Erysi- 
phacese (Phjdlactinia). See p. 187. 

O. ulmorica Del. causes a mildew of mulberries.^^^ 

Pellicularia Cooke (p. 577) 

Hyphse creeping, branched, septate, in a subgelatinous pellicle, 
conidia sessile. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



583 



A single species. P. koleroga Cke. causes a coffee leaf rot in 
India and has been reported by Fawcett -^^ as causing serious leaf 
blight of the same host in the West Indies. 



Verticillieae (p. 5G6) 
Conidia acrogenous, on verticillate branches of the conidiophore. 

Key to Genera of Verticillieae 

Conidia solitary or loosely grouped, not in 
chains 
Conidia-bearing branches very short, am- 

pulliform 1. Pachybasium. 

Conidia-bearing branches terete or longer 
Conidia globose to ovoid 
Tips of branches clavate, in twos 

rectangularly 2. Verticilliopsis, p. 584. 

Tips of branches not as above 

Conidia conglutinate into a stra- 
tum 3. Corymbomyces, p. 584. 

Conidia not conglutinate 

Conidia separating readily from 

the tips 4. Verticillium, p. 584. 

Conidia separating with dif- 
ficulty from the tips 5. Cladobotyrum. 

Conidia cylindric or elongate 

Conidia-bearing branches or sporo- 
phores 1-spored 

Sporophores straight 6. Acrocylindrium. 

Sporophores uncinate 7. Uncigera. 

Sporophores scveral-sporcd 
Sporophore inflated verrucose at 

apex 8. Calcarisporium. 

Sporophore incurved, with seriate 

conidia below 9. Coemansia. 

Conidia capitate or densely spicate, not in 
chains 
Conidia sessile 

Conidia capitate, involved in mucus 

Fertile hyphse smooth 10. Acrostalagmus, p. 584. 

Fertile hyphaj asperate 11. Gloeosphaera. 



584 THE FUNGI WHICH CAUSE PLANT DISEASE 

Conidia densely spirally spicate at 

apices 12. Clonostachys. 

Conidia on small stalks 13. Sceptromyces. 

Conidia in chains 14. Spicaria, p. 585. 

Verticillium Nees (p. 583) 

Hyphse creeping; conidiophores erect, verticellately branched; 
conidia borne singly at the apex of the branchlets, globose-ovoid, 
hyaline or light colored. 

A genus of some seventy-five species, which are in the main 
conidia of various species of Hypocreales. See p. 196. 

V. albo-atrum McA. is a weak wound parasite of the potato. 

Verticilliopsis Cast (p. 583) 

Fertile hyphse with verticillate branches, 2 or 3 at each node; 
fertile branches clavate; conidia in heads, surrounded by a slime. 
A monotypic genus. 

V. infestans Cast, infects mushrooms in culture. 

Corymbomyces Appel & Strunk (p. 583) 

Sterile hyphse creeping; fertile hypha3 erect, septate, dichoto- 
mous corymbose; conidia ellipsoid, clustered in gelatinous masses 
at the apex of the branches. 

A single species, C. albus Appel & Strunk. on cacao in Africa. 

Acrostalagmus Corda (p. 583) 

Hyphse creeping; conidio- 
phores erect, septate, richly 
verticillately branched; conidia 
borne in slimy heads on the 
s|[^ ^^^^S^^^^^ enlarged end of the secondary 
branches. 

About fifteen species. 

Fig. 390.— Cross-section of a vascular ^' ^^^US Preu. 

bundle. Acrostalagmus threads in the Hyphse cespitose, efifuse, slen- 
vessels. After Van Hook. , i • 

der, subangular, contmuous or 

septate, conidiophores, 200-220 x 1.7-2 n, erect; fertile branches 

continuous, straight or curved; conidia in spherical heads, 9-10 n 




THE FUNGI WHICH CAUSE PLANT DISEASE 



585 



in diameter, numerous, minute, elliptic oblong, 3.3-3.4 x 1-1.5 m, 
hyaline. 

It causes a wilt of ginseng. The vascular bundles are yellowed 
and the ducts plugged by the 
mycelium. Entrance is apparently 
through the leaf scars. The fungus 
was isolated by Van Hook ^^® and 
cultural studies made. In a later 
article Rankin ^"'^ has discussed what 
appears to be this fungus under the 
name A. panax. 

A. vilmorinii Gue.^^^'^^^ causes a 
disease of China asters and a species 
closely related, one of cacao fruits. 

Spicaria Harz (p. 584) 

Hj'phse creeping; conidiophores 
erect, much branched; conidia apical, fig. 391.— Spore-bearing stalks of 
catenulate, ovate or elongate, hyaline fp^o^eraJe^borL^in heads"and?r: 

or dilute colored. held together at first by a coat 

of slime. After Van Hook. 

About ten species. 

S. solani Hart, is said to produce effects on the potato much 
like those of Fusarium solani. '^^^ 

S. colorans v. Hall, the cause of cacao cankers is probably a 
conidial stage of Calonectria cremea. See p. 205. 

Moniliaceae-Didymosporeae (p. 565) 

Conidia hyaline, or bright colored, 1-septate, ovoid oblong or 
short fusoid. 




Key to Genera of Moniliaceae-Didymosporeae. 

Conidia not in chains 
Saprophytic or on fungi 
Conidia smooth 
Fertile hyphse simple or nearly so 
Hyphte inflated at apex or joints 
Hyphse denticulate, inflated at 

apex; conidia fusoid 1. Diplorhinotrichum. 



586 THE FUNGI WHICH CAUSE PLANT DISEASE 

Hyphse inflated at both apex 

and joints 2. Arthrobotrys. 

Hyphse not inflated 
Conidia spirally pleurogynous 3. Haplariopsis. 
Conidia solitary, acrogenous 
or capitate 
Conidia capitate at apex. . . 4. Cephalothecium, p. 586. 
Conidia solitary at apex 

Fertile hyphse long 5. Trichothecium. 

Fertile hyphse very short 6. Didymopsis. 
Fertile hyphse branched 

Branching irregular 7. Diplosporium. 

Branching verticillate 8. Diplocladium. 

Branching dichotomous; sterig- 

mata subternate 9. Cylindrocladium. 

Conidia echinulate; conidial cells un- 
equal 10. Mycogone, p. 587. 

Biophilous 

Conidia obliquely beaked 11. Rhynchosporiuni,p. 587. 

Conidia not beaked 
Hyphse mostly simple, not spirally 

twisted 12. Didymaria, p. 587. 

Hyphse simple, spirally twisted ... 13. Bostrichonema. 
Conidia catenulate 

Fertile hyphse simple, short 14. Hormiactis. 

Fertile hyphffi verticillately branched. . 15. Didymocladium. 

Cephalothecium Corda 

HyphsB prostrate ; conidiophores erect, 
simple, septate, conidia apical, siibcapi- 
tate, oblong to pyriform, hyaline. 
Five species, chiefly saprophytes. 
C. roseum Cda.^^*^^^^ 
Cespitose in subrotund, rose colored 
spots, fading with age, byssoid; hyphse 
Fig. 392.— Spores of Cepha- creeping, branched; conidiophores erect, 
Eistir '°''''°'' ^^^^"^ simple, continuous, hyaline; conidia 
oblong-ovate, constricted at the septum, 
capitate, light rose. 
It is often found following apple scab gaining entrance through 




THE FUNGI WHICH CAUSE PLANT DISEASE 



587 



the injured cuticle and causing rot. A ring of pink conidiophores 
and conidia is formed around tlie margin of the scab. Inoculation 
tests showed the fungus unable to penetrate through sound cuticle 
though it readily made entrance through wounds. It has been 
occasionally reported on living twigs and leaves and as a common 
saprophyte has long been known. The first account of it in America 
was from New York -^° in 1902 though it was described in 1899 as 
injuring pears in Germany."®" 

Mycogone Link (p. 586) 

Hyphse intricately branched; conidiophores 
short, lateral; conidia unequally 2-celled, the 
upper larger, echinulate. 

There are about fifteen species of mycogenous 
fungi which are probably conidial stages of Hy- 
pomyces. See p. 200. 

M. perniciosa Mag."^^' -®^ 

White throughout, byssoid, deforming the 
host; conicUophores short; conidia solitary, 
more or less pyriform, almost colorless, 17- 
22 X 9-12 n. 

It is reported by Mrs. Patterson as the 
cause of a mushroom disease in America. 
A verticillium conidial stage was present but 
no ascigerous form. 

M. rosea Link, also occurs on mushrooms. 

Rhynchosporium Heinsen (p. 586) 

On leaf spots; hypha? filiform, hyaline, creeping, septate; conid- 
iophores erect, with incurved branches, hyaline, apically denticu- 
late; conidia short-cylindric, with a short oblique beak, medially 
septate, hyaline. A monotypic genus. 

R. graminicola Hein. occurs on rye, wheat, and barley in Europe. 

Didymaria Corda (p. 586) 

Conidiophores simple, conidia borne apically, ovate, hyaline. 

About twenty species of leaf parasites. 

D. prunicola Cav, produces spots on plum leaves. 




Fig. 393. — Mycogone, 
conidiophores and 
conidia. After Sac- 
cardo. 



588 THE FUNGI WHICH CAUSE PLANT DISEASE 



Moniliaceae-Phragmosporae (p. 565) 

Conidia hyaline or bright colored, 2 to several-septate, oblong, 
fusoid or elongate. 

Key to Genera of Moniliaceae-Phragmosporae 

Fertile hyphte very short and little dif- 
ferent from the conidia 
Conidia in chains, cylindric or oblong.. 1. Septocylindrium, p. 589. 
Conidia not in chains 

Sporophore 3-celled, upper cell much 

inflated 2. Milowia. 

Sporophore not inflated, sometimes 
obsolete 
Conidia ciliate at apex and upper 

septum 3. Mastigosporium, p. 590. 

Conidia not ciliate 

Hyphse lacking; conidia not ag- 
gregate 4. Fusoma, p. 590. 

Hyphse distinct; conidia ag- 
gregate 
Conidia in mucose glomerules . 5. Rotaea. 
Conidia in fascicles, not mu- 
cose 6. Paraspora. 

Fertile hyphse manifest and distinct from 
the conidia 
Saprophytic 

Conidia solitary or at least not capi- 
tate 
Fertile hyphse simple 

Sterile hyphse lacking 7. Dactylella. 

Sterile hyphse abundant 8. Monacrosporium. 

Fertile hyphse branched 

Hyphse verticillately branched. . 9. Dactylium. 
Hyphse irregularly branched. . . 10. Blastotrichum. 
Conidia capitate 
Fertile hyphse vesiculose at tip. . . 11. Cephaliophora. 
Fertile hyphse not swollen 

Hyphse simple, sterile lacking . . 12. Dactylaria. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



589 



HyphiE verticillate; sterile hy- 

phcc present 13. Mucrosporium. 

Parasitic 

Conidia mucose-conglobate, allan- 

toid, often continuous 14. AUantospora. 

Conidia not mucose-conglobate 
Conidia ovate-cylindric or elon- 
gate, often catenulate 15. Ramularia, p. 590. 

Conidia obclavatc-pyriform 16. Piricularia, p. 591. 



Septocylindrium Bonardin (p. 588) 

Conidiophores very short, scarcely distinct from the conidia, 
or in parasitic species distinct but short and inflated or dentic- 
ulately sublobate at the apex; conidia oblong or cylindrical, one 
to many-septate, catenulate, the chains often branched. 

About thirty species, a few of them of economic impor- 
tance. 

S. areola (Atk.) P. & C.-''' ''' 

Spots amphigenous, pale, becoming darker in age, 1 to 10 mm., 
angular, limited by the veins of the leaf, conidiophores amphig- 
enous, fasciculate, sub- 
nodose, branched or not, ^i( 

several times septate, 
hyaline, 25-75 x 4-7 ju; 
conidia oblong, usually 
abruptly pointed at the 
ends, catenulate or not, 
14-30 X 4-5 /x, hyaline. 

Leaf spots are pro- 
duced on cotton. The F^«- 394.— S. areola. After Atkinson. 
conidia and stalks are so a])undant on the undersides of spots as 
to give them a frosted appearance. 

S. rufomaculans (Pk.) P. & C. 

Spots numerous or confluent and even covering the entire leaf, 
reddish; conidiophores very short, hypophyllous, cespitose; conidia 
catenulate, variable, ellipsoid-oblong to cylindric, hyaline, 8-16 x 
3-4 n. 

It is somewhat injurious on buckwheat in America.^^^ 




590 THE FUNGI WHICH CAUSE PLANT DISEASE 

S. radicicolum Aderh ^''^ is reported by Aderhold as the cause of 
death of roots of Prunus and Pyrus. 

Mastigosporium Riess (p. 588) 

Conidiophores short, stipitate, continuous, hyaline, conidia fu- 
soid, large, 3-septate, hyaline, with apical and subapical bristles. 
A small genus in part = Dilophia. 

Fusoma Corda (p. 588) 

Mycelium obsolete or poorly developed; conidia innate, fusiform 
separate. 

F. parasiticum Percival, causes a wilt of hops.^^^ 

Ramularia Unger (p. 589) 

Conidiophores fasciculate, simple or with short, scattered 
branchlets, often flexuose, nodulose, or denticulate towards the 
apex, hyaline or light colored; conidia acrogenous or acropleuro- 
gjTious on the denticulations, hyaline, sometimes subcatenulate, 
oblong, cylindric, typically many-septate. 

About three hundred species. In part =Mycosph8erella. See 
p. 243. 

R. tulasnei Sacc. on strawberry =Mycosph8erella fragariae. See 
p. 244. 
R. armoraciae FcL^^ 

Spots amphigenous, subochraceous becoming gray; conidiophores 
fasciculate, continuous, subsimple, 40-50 x 
2.5-3 ju; conidia rod-shaped, obtuse, hyaline, 
15-20 X 3-4 n. 
On horseradish causing leaf spots. 
R. taraxaci Karst, 

Hypophyllous, spots purple-margined, hyphse 
35-45 X 2-3 /x, spores bacillar, simple, straight, 
hyaline, 18-30 x 2-3 fx. 

Fig. 395. — R. armora- ^ , , ,. 

cite. After Sac- On dandelion. 

^^^^^- R. spinaciae Nip. is on spinach; 

R. betas Rost. on beet; 

R. necator Mas. on cacao; 




THE FUNGI WHICH CAUSE PLANT DISEASE 



591 



R. geranii (West.) Fcl. on cultivated geraniums 

R. primulae Thiim. 

Spots rounded-angular, subochraceous, emarginate; conidio- 
phores amphigenous, 50-60 x 5 ix, continuous, somewhat denticu- 
late, rarely branched; conidia fusoid-cylindric, 20-30 x 3-6 ii, con- 
tinuous or 1-septate. On Primula.-^ 

R. lactea (Desm.) Sacc. is on violets; 

R. heraclei (Oud.) Sacc. on cultivated Heracleums; 

R. onobrychidis P. & D. on leaves of sainfoin. 

R. cynarae Sacc. causes loss of artichokes in France and Africa. 

R. coleosporii Sacc. is on sweet potato in Porto Rico.^^^ 

R. modesta Sacc. is recorded for the strawberry. 

R. narcissi Chit, and R. vallambrosae Br. & Cav. cause disease 
of leaves and stalks of Narcissus.-™ 

R. goeldiana Sacc. kills twigs of coffee. 



Piricularia Sacc. (p. 589) 

Conidiophores simple, rarely branched, 
conidia obclavate to pyriform, 2 to many- 
septate, solitary acrogenous, hyaline. 

A small genus of parasites. 

P. grisea (Cke.) Sacc.^^^'^^^ produces 
pallid or water-soaked, spots on culms 
and leaves, with age greyish; conidio- 
phores in clusters of two or five from 
the stomata, simple or rarely sparingly 
branched, greyish, septate; conidia sin- 
gle, terminal in scorpioid cymes, ovate, 
2-septate, 24-29 x 10-12 n. 

It causes death of rice plant tissue and 
the disease called "blast." If affected 
leaves or stalks be placed in a damp at- 
mosphere for about a day a delicate 

greyish fungus, the sporing mycelium appears. The fungus grows 
well in culture and applied to the rice plants gives rise to the 
typical disease spots. This species was originally described on 
Digitaria sanguinalis and the form on rice has been called 




Fig. 396. — Piricularia grisea. 
a, conidiophores. h, ger- 
minating spores. After 
Fulton. 



592 THE FUNGI WHICH CAUSE PLANT DISEASE 

P. oryzae; but morphological characters and inoculation experi- 
ments indicate their identity on various other grasses. 

P. caudata A. & S. occurs on cacao. 

To the Moniliaceae-scolecosporae belongs only one genus : 

Cercosporella Saccardo 

Hyaline throughout; conidiophores simple or branched; conidia 
filiform, many-septate. Distinguished from Cercospora only in 
color. The genus contains some seventy species 
of parasites. 

C. persicae Sacc.^^^ 

Conidiophores cespitose, on discolored areas, 
filiform, 2 to 3-branched, continuous; conidia 
40-60 X 1-5 fi, torulose. 

The conidia develop in abundance on the 
lower sides of leaf spots of peach causing a 
frosty mildew. 

C. narcissi Bond, occurs on Narcissus; 
C. inconspicuus (Wint. & Hohn) on lily. 
J ^ C. pastinacae Karst. 

Fig. 397. — C. per- Spots amphigenous, fuscus or whitish; conidia 
card'o. ^^*^^ ^^°" filiform, somewhat curved, slender, attenuate, 

50-90 X 2 M- 
On parsnip and other Umbelliferse. 
C. albo-maculans E. & E. 

Spots orbicular, white, dark-margined, conidiophores amphige- 
nous, cespitose, 8-12 x 2 ju, hyaline, continuous; conidia cylindric, 
40-68 X 2-2.5 /x, straight or curved, 3-septate. 
A common cause of pale spots on turnip leaves. 

Moniliaceae-Dictyosporeae (p. 565) 

Conidia hyaline or bright colored, muriform, globose, ovoid 
or cubic. 

Key to Genera of Moniliaceae-Dictyosporese 

Saprophytic 

Hyphse much-branched; conidia elliptic 

or globose, cells uniform 1. Stemphyliopsis. 




THE FUNGI WHICH CAUSE PLANT DISEASE 593 

Hyphse little-branched; conidia six-lobed 
and sarcinceform, central cell larger, 

colored, lobes hyaline 2. Synthetospora. 

Parasitic 3. Hyalodema, p. 593. 

This group contains but one important pathogen, Hyalodema 
evansii Mag., recently described by Magnus -''^ on Zizyphus in 
Africa. 

The Moniliaceae-Helicosporae contain no important parasites. 

Moniliaceae-Staurosporae (p. 565) 

Conidia hyaline or bright colored, stellate, radiate or forked, 
septate or continuous. 

Key to Genera of Moniliaceae-Staurosporae 

Hyphse lacking; conidia trident-shaped. ... 1. Tridentaria. 
Hypha; present 

Conidia globose to cylindric, permanently 
attached to 2 or 3 divergent sterig- 

mata 2. Tetracladium. 

Conidia themselves stellate or radiate 
Conidia bilobate-forked; lobes parallel, 

contiguous 3. Pedilospora. 

Conidia narrowly digitate 4. Prismaria. 

Conidia 3 to 4-radiate 

Conidia ciliate at the apex 5. Titaea, p. 593. 

Conidia muticate 

Conidia 3-radiate 6. Trinacrium. 

Conidia 4-radiate 

Fertile hyphaj very short, simple 7. Tetracium. 
Fertile hyphse branched 8. Lemonniera. 

Titeae Saccardo 

Conidiophores simple, continuous; conidia subradiately 4 to 5- 
celled, the cells unequal in size. 

A small genus of little economic importance. 

T. maxilliformis Rost. has been found on the roots of clover in 
Denmark. 2^^ 



594 THE FUNGI WHICH CAUSE PLANT DISEASE 



Dematiaceae (p. 565) 

Hyphse dark or black, cobwebby, loose, usually rigid, not coher- 
ing in definite fascicles; conidia typically dark and concolorous, 
but sometimes the hyphse are dark and conidia clear, or the conidia 
dark and the hyphse clear. This family parallels the Moniliacese 
and certain intermediate forms must be sought in both. 

Key to Sections op Dematiaceae 

Conidia globose, ovate, oblong or short 
cylindric 

Conidia continuous 1. Amerosporae, p. 594. 

Conidia 2-celled 2. Didymosporae, p. 601. 

Conidia 3 or more-celled 3. Phragmosporae, p. 608. 

Conidia muriform 4. Dictyosporae, p. 615. 

Conidia long, filiform or vermicular 5. Scolecosporae, p. 625. 

Conidia cylindric, spiral or convolute, typi- 
cally septate 6. Helicosporae. 

Conidia of several stellately grouped cells. . . 7. Staurosporae. 

D ematiacese-Amerosporse 

Conidia continuous, globose to oblong. 

Key to Subfamilies of Dematiaceae-AmerosporSB. 

Conidiophores very short, scarcely distin- 
guishable from the mycelium 

Conidia borne singly 1. Coniosporieae, p. 595. 

Conidia catenulate 2. Toruleae, p. 595. 

Conidia in heads or racemes 3. Echinobotryeae. 

Conidiophores manifest and distinct from 
the mycelium and spores 
Conidia dark, rarely subhyaline 
Conidia not in chains 

Conidia capitate 4. Periconiese, p. 597. 

Conidia verticillate, or at least lat- 
eral 5. Anthrinieae. 

Conidia borne singly on short 

lateral branches 6. Trichosporieae, p. 598. 



THE FUNGI WHICH CAUSE PLANT DISEASE 595 

Conidia solitary, acrogcnous 7. Monotosporeae, p. 600. 

Conidia in chains 8. Haplographieae, p. 600. 

Conidia hyaline 

Conidia acrogcnous on short hctcromor- 
phic conidiophorcs at tlie lower 
part or bases of erect hyphai 

Conidia single or catenulate 9. Sarcapodieae. 

Conidia in heads 10. Myxotrichelleae. 

Conidia on hypha? of the same kind 

Conidia in heads 11. Stachylidieae. 

Conidia in chains 12. Chalarieae. 

Conidiosporieae (p. 594) 
Conidia not catenulate, conidiophores short. 

Key to Genera of Coniosporieae 

Conidia spherical, elliptic or discoid 1. Coniosporium, p. 595. 

Conidia elongate 2. Fusella. 

Coniosporium Link 

Hyphse very much reduced; conidia dark, 
globose, ovoid or discoid, borne on short hya- 
line conidiophores. '^ 

.,..,.« . ^ • n 1, Fig. 398. — Conio- 

About eighty-five species, chiefly saprophytes. sporium. After 
C. onobrychidis Mag. occurs on sainfoin; Saccardo. 

C. filicinum Rost. on Pteris and other ferns. 

Toruleae (p. 594) 
Conidia in chains. 

Key to Genera of Toruleae 

Conidia of two sorts, macroconidia catenul- 
ate 

Microconidia glomerate 1. Heterobotrys. 

Microconidia internal, catenulate 2. Thielaviopsis, p. 5C6. 

Conidia all alike 
Hyphce dark 

Chains breaking up readily 
Conidia globose or ovoid 3. Torula, p. 597. 



596 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Conidia clavate 4. Gongromeriza. 

Chains breaking up with difficulty 

Chains curved 5. Gyroceras. 

Chains straight or nearly so 6. Hormiscium. 

Hyphse hyaline 7. Monilochaetes, p. 597. 

Thielaviopsis Went. -'' (p. 595) 

Hyphse creeping, subhyaline; conidiophores simple, septate; 
conidia of two kinds; macroconidia catenulate, ovate, fuscous; 




■T. ethaoeticus. 
Wakker and 




Fig. 400.— Torula. 
Saccardo. 



After 



microconidia cylindric, hyaline, catenulate within the conidiophore. 
In part=Trichosphaeria. 

Only two species, both of economic importance. 

T. paradoxa (d. Seyn) v. Hohn (=Chalara paradoxa.) 

Macroconidia 16-19 x 10-12 /x; microconidia 10-15 x 3.5-5 /jl. 

It is the cause of a pineapple rot, in which role it was first de- 
scribed in 1886; and of a sugar cane disease.'" 

In addition to micro and macrospores the fungus possesses a 
pycnidial form. With variation of the substratum the spores vary 



THE FUNGI WHICH CAUSE PLANT DISEASE 597 

considerably from the typical. In disinfection tests Patterson and 
Charles ^^ showed the macrospores to be considerably more resist- 
ant than the microspores, also that fumigation kills superficial 
spores and spores placed in incisions in the fruit. 

T. podocarpi Pet. is known from Podocarpus roots.^^^ 

Torula Persoon (p. 595) 

Hyphae decumbent; conidiophores short, scarcely different 
from the conidia, which are catenulate, breaking away singly or in 
groups, dark to black, oblong to fusoid, smooth or roughened. 

Some one hundred fifty species, chiefly saprophytes. 

T. exitiosa d. Seyn is said to cause much injury to chestnuts. 

T. sphaerella Cke. causes a sooty mold of coffee. 

Monilochaetes Ellis & Halsted (p. 596) 

Hyphae brown; conidiophores obsolete or very short, conidia 
like; conidia in chains, moniliform, dark; some chains interspersed 
with larger conidia. 

Monotypic and poorly known. 

M. infuscans Ell. & Hals.^^'' 

The mycelium grows subepidermally in sweet potato roots 
causing discoloration and withering. The conidiophores arise 
from the surface bearing their simple chains of conidia. 

Periconieae (p. 594) 
Conidia dark, capitate. 

Key to Genera of Periconieae 

Fertile hyphse simple, but often with short 
apical branches 
Hyphse with apical branches or conidio- 
phores 

Parasitic 1. Periconiella. 

Saprophytic 
Apex with heterogeneous conidio- 
phores 
Apex swollen; conidiophores 3 to 4 2. Haplobasidium. 



598 THE FUNGI WHICH CAUSE PLANT DISEASE 

Apex not swollen; conidiophores 

many 3. Stachybotrys. 

Apex short-branched, rarely simple 
Apex short-branched or simple 

Apex not swollen 4. Periconia, p. 598. 

Apex swollen 5. Stachybotryella. 

Apex capitate-branched; branches ' 
2 to 3-furcate and spine- 
bearing 6. Cephalotrichum. 

Hyphse without apical branches or co- 
nidiophores 

Conidia globose 7. Trichobotrys. 

Conidia boat-shaped curved; hypha) 

dark-ringed 8. Camptoum. 

Conidia fusoid, sometimes subhya- 

line 9. Acrotheca. 

Fertile hyphse branched below the apex 
Hyphse forked below apex; conidia ob- 
long 10. Synsporium. 

Hyphse repeatedly dichotomous; conidia 

globose or elliptic 11. Dicyma. 

Periconia Bonordin -^^ 

Hyphffi creeping, or obsolete; conidiophores simple, dark, 
apically fertile; conidia globose*, fuscous, solitary on short sterig- 
raata. Fig. 401. 

Some forty species chiefly saprophytes. 

Trichosporieae (p. 594) 
Conidia dark, borne singly on short lateral branches. 

Key to Genera of Trichosporieae 

Hyphse loose, typically saprophytic 

Hyphse vesiculose-inflated here and there 

Conidia-bearing vesicles pleurogynous. 1. (Edemium. 

Conidia-bearing vesicles acrogenous ... 2. Cystophora. 
Hyphse not vesiculose-inflated 

Fertile hyphse erect 



THE FUNGI WHICH CAUSE PLANT DISEASE 599 

Branches circinate at apex; conidia 

mesogcnous, muricate 3. Acrospeira. 

Branches spirally twisted; conidia 

exogenous 4. Streptothrix, p. 509. 

Hypha; simple or with straight 

branches 5. Virgaria. 

All hyphce more or less creeping 

Branches curved or lash-like. . . 6. Campsotrichum. 

Branches not curved 

Conidia spiny, rarely smooth 7. Zygodesmus, p. 599. 

Conidia smooth 

Conidia sessile 8. Trichosporiuin. 

Conidia on stalks 

Conidia on tooth-like sterig- 

mata 9. Rhinocladium. 

Conidia on jar-like stalks .... 10. Basisporium. 
Hyphae forming a crust, parasitic 11. Glenospora. 



Streptothrix Corda 

Conidiophores erect, monopodially branched, 
the branches spirally coiled; conidia apical or 
lateral, single, sessile or with short sterigmata, 
dark colored. 

A small genus. S. dassonvillei Broc-Ros. is 

noted as the cause of mold of grain and fod- 
der.337 

Zygodesmus Corda 

Hyphie and conidiophores creeping, the lat- 
ter branched, light or dark colored, here and 
there irregularly inflated, septate at the swel- 
lings; conidia globose or ovate, muricate, rarely 
smooth, on short sterigmata or on basidia-like 
branches of the sterigmata. 

Some fifty species, chiefly non-parasitic. 

Z. albidus E. & H.^^ 

Halsted describes a disease characterized by a floury coating 
on violet leaves and ascribes it to this species. 




Fig. 401. — Periconia. 
After Saccardo. 



600 THE FUNGI WHICH CAUSE PLANT DISEASE 

Monotosporeae (p. 595) 
Conidia dark, solitary, acrogenous. 

Key to Genera of Monotosporeae 

Sterile hyphae lacking 

Fertile hyphse short and fascicled at 

base 1. Hadrotrichum, 

Fertile hyphse longer, separate 2. Monotospora. 

Sterile hyphse present 

Conidia with a loose hyaline membrane . 3. Nigrospora. 
Conidia without a membrane 

Conidia with a large shining drop. . . 4. Sporoglena. 
Conidia without a shining drop 5. Acremoniella, p. 600. 

Acremoniella Saccardo 

Hyph£e creeping, simple or ramose, hyaline or colored; conidio- 
phores simple, short, subbulbous below; 
conidia globose to ovoid, fuscous. 
About a dozen species. 
A. occulta Cav.-^'' forms brownish-yellow 
flakes on the stems of cereals; 

A. verrucosa Togn. on wheat in 
A 't\\^ Al .y:^ Italy. 

Fig. 402.-Acremoniella. Haplographicae (p. 595) 

After Bonorden. /-, • i- i i 

Conidia dark, catenulate. 
Key to Genera of Haplographieae. 

Sterile hyphse all creeping or obsolete 
Fertile hyphse simple, not branched at tip 

Chains of conidia lateral 1. Dematium. 

Chains terminal 

Conidia without isthmi 2. Catenularia. 

Conidia connected by cylindric 

isthmi 3. Prophytroma. 

Fertile hyphse branched 

Hyphse dendroid 4. Hormodendrum, p. 601. 





THE FUNGI WHICH CAUSE PLANT DISEASE 601 

Hyphse capitate branched at tip. . . . 5. Haplographium. 
Some sterile hyphse erect and mixed witli 

the fertile 6. Hormiactella. 

Hormodendrum Bonarden (p. 600) 

Hyphse creeping; conidiophores erect, septate, brown, variously 
dendritically branched; conidia catenulate on 
the branches, globose, ovoid, olivaceous to 
fuscous. 

About a dozen species. 

H. hordei Bruhne on barley stems and 
leaves often reduceg the yield. 

Spots brown, scattered over the entire leaf or 
confluent, oblong; hyphse simple, septate; co- 

... . ,. 1 • 11 1 ij^ Fig. 403. — H. hordei 

nidia various, cylmdric, rounded or su batten- After Bruhne. 
uate, or ellipsoid to subglobose, verrucose. 

Dematiaceae-Didymosporae (p. 594) 
Conidial 1-celled, dark, rarely hyaline, ovoid or oblong. 

Key to Genera of Dematiaceae-Didymosporae 

Hyphse very short or scarcely different from 
the conidia 
Conidia not in chains 

Hyphse lacking 1. Dicoccum, p. 602. 

Hyphse present, circinate 2. Cycloconium, p. 602. 

Conidia in chains 3. Bispora. 

Hyphse distinctly different from the conidia 
Conidia smooth, muticate 
Conidia not capitate 
Conidia more or less catenulate at 
first 
Hyphse and conidia biform, the 
latter 1-celled or continuous, 

dark or hyaline 4. Epochnium. 

Hyphse and conidia uniform 

Hyphse here and there inflated 5. Cladotrichum, 



602 THE FUNGI WHICH CAUSE PLANT DISEASE 

Hj'phse not inflated 

Hyphse erect; conidia long- 

catenulate 6. Diplococcium, p. 603. 

Hyphse somewhat decumbent ; 
conidia short-catenulate 

or finally solitary 7. Cladosporium, p. 606, 

Conidia not catenulate 

Hyphse beautifully flexuose- 

torulose 8. Polythrincium, p. 603. 

Hyphse not torulose or flexuose 
Hyphse inflated at tip, branched 9. Pseudobeltrania. 
Hyphse not inflated, usually 
short and little branched 
Conidia merely acrogenous 
Conidiophores short, 1 or 2- 

septate 10. Fusicladium, p. 606. 

Conidiophores rather long, 

multiseptate 11. Passalora, p. 607. 

Conidia acro-pleurogenous . . . 12. Scolecotrichum, p. 607. 

Conidia capitate 13. Cordana. 

Conidia muriculate or ciliate 

Conidia muriculate 14. Trichocladium. 

Conidia ciliate at apex; fertile and 

sterile hyphse intermixed 15. Beltrania. 

Dicoccum Corda (p. 601) 

Hj'^phse creeping, chiefly very short, simple; conidia elongate 
or short-clavate, dark. 
About a dozen species. 
D. rosae Bon. produces spots on rose leaves. 

Cycloconium Castaigne (p. 601) 

Hyphae in the walls of the epidermis, dichotomous branched, 
very fugacious, black; conidia ovoid, solitary. 

There is one species: 

C. oleaginum Cast. Mycelium circinate, fugacious, black; 
conidia sessile, ovoid, yellow-green. 

It forms blotches on olive leaves and on peduncles of the fruit 
in Italy and France and is somewhat injurious in California. ^^^ 



THE FUNGI WHICH CAUSE PLANT DISEASE 603 



Diplococcium Grove (p. 602) 

Conidiophores erect, septate, branched, olivaceous; conidia 
catenulate, 2-celled. 





Fig. -104. — Cycloconium 
oleaginum. After Boyer. 



Fig. 405.— Clodosporium cu- 
cumerinum, mycelium, a 
hyphal knot, conidiophore 
and spores. After Hum- 
phrey. 



D. conjunctum (Bon) Sacc. is reported as a parasite of the 



geranium 



Cladosporium Link (p. 602) 



Hyphffi decumbent, intricately-branched, olivaceous; conidia 
globose to ovoid, greenish. In part=Mycosphffirella. See p. 243. 

Some one hundred seventy-five species, many of them of 
economic importance. 

C. fasciculare Fr. on hyacinth =Pleospora hyacinthi. See p. 260. 

C. herbarum (Pers.) Lk. on many hosts = My cosphserella tu- 
lasnei. See p. 247. 



604 THE FUNGI WHICH CAUSE PLANT DISEASE 

C. herbarum (Pers.) Lk. var. citricolum.^^^- 22 
Fawcett ^^^ recognizes this as the cause of scaly bark of Citrus. 
The fungus was grown in pure culture and inoculations were made 
resulting in from forty to sixty days in typical spots. From these 
the fungus was re-isolated, 

C. cucumerinum E. & kP' ^s^-ss? 

Effused, maculose; in mass greyish-brown, changing to dark 
olivaceous, forming spots on fruits; condiophores cespitose, 
sparingly septate, simple, denticulate, pale; conidia ovoid, lemon- 
shaped or fusoid; olivaceous, 10-13 x 3-4 ju. It causes watery 
spots on cucumber leaves, also decayed spots in fruit. 

C. elegans Penz. is the cause of disease on various Idnds of 
oranges in Italy. This species is in the literature much confused 
with the next. 

C. citri Mas.^3' 288-291 

Conidiophores tufted, erect, branched, septate, brown, 30-75 
X 2-4 11; conidia fusiform, dusky, continuous, or 1 to 3-septate, 
8-9 X 2.5-4 n. 

The cause of scab on lemons, sour oranges, satsumas and pom- 
elos. It was grown in artificial culture by Fawcett. 
C. carpophilum Thum.^e- 292-294. 459 

Spots orbicular, often confluent, blackish-green, forming circles; 
conidiophores erect, simple, sinuous, septate; conidia 
ovate, obtuse, continuous or 1-septate, 10-12 x 
4-6 fi. 

This is the cause of the widely distributed scab 

of peach, plum, nectarine, apricot, cherry. The 

deep olive-broAvn hyphse are found intermingled 

with the hairs of the peach. The disease was first 

noted in Austria in 1877. The fungus was cultured 

carpophilum.' and inoculations were made by Chester.^^^ 

After Cobb. jj^ ^j^g ^^jg ^j^g fungus breaks the cuticle from 

the layers below and its hyphae project through cracks. Upon the 

leaf it causes shot holes. 

C. sicophilum Far. attacks fig fruits. 
C. fulvum Cke.32 

Conidiophores densely crowded rupturing the cuticle, sparingly 
branched, septate, nodulose, bearing a few conidia near the apex; 




THE FUNGI WHICH CAUSE PLANT DISEASE 



605 



conidia elliptic-oblong, 1-septate, translucent, tawny, 10-20 x 4- 
6 yL. 

The hyphae are abundant on the lower sides of tomato leaves, 
forming a mold, varying from whitish to purplish in color. 

It causes serious disease in Europe and America. 

C. condylonema Pass, is found on leaves of Prunus causing leaf 
spot nnd curl. 

C. bigarardia is on Citrus. 

C. macrocarpum Preu.-° 

Subeffuse, black; conidiophores subfasciculate, simple, some- 




FiG. 407.— C. fulvum. After Southworth. 



what flexuose, brown; conidia oblong, oblong-ovate, 2 to several 
septate, obtuse, pale brown. 

On spinach leaves in New Jersey, causing disease. 

C. graminum Cda. 

Clusters minute, irregular, scattered, greyish-brown; conidio- 
phores distinct, erect, simple, nodulose-flexuose, brown; co- 
nidia concolorous, continuous to several-celled, rounded or 
oblong. 

It is reported that this fungus was commonly present on sterile 
wheat florets and that inoculation with it increased such sterility 
slightly. 

C. cryzae S. & Sy. is on rice; 

C. orchidis C. & M. on Oncidium; 

C. pisi Cu. & Ma. on Pisum. 



606 THE FUNGI WHICH CAUSE PLANT DISEASE 

C. peoniae Pass. 

Spots large, chestnut brown, hyphse short, simple; spores 
various, long, 1 to 2-septate. On peony. 

C. epiphyllum Mart, is on oak, sycamore, poplar, etc. ; 

C. juglandis Cke. on walnut; 

C. scribnerianum Cav. on beech; 

C. hypophyllum Fcl. on elm; 

C. tuberum Cke. on sweet potato tubers; 

C. scabies Cke. on tomato and cucumber; 

C. oxycocci Sh. on cranberry. 

C. zeae Pk. 

Sterile hyphse hyaline, sub-cutaneous, erumpent ; spores elliptic- 
oblong, 4 X 20 jLi, continuous or 1 to 3-septate. 

In immature corn grains. 

C. brunneo-atrum McA. is on orange leaves and young shoots 
in Australia; 

C. javanicum Wak. on sugar cane in Java causing root molds. 

Polythrincium Kunze & Schmidt (p. 602) 

Conidiophores erect, fasciculate, regularly flexuose or toru- 
lose, black, simple; conidia acrogenous, obo- 
void. 

Monotypic. In part =Phyllachara. See 
p. 220. 

P. trifolii Kze. on clover =Phyllachora tri- 
folii. See p. 220. 

Fusicladium Bonardin (p. 602) 

Conidiophores short, erect, straight, spar- 
FiG. 408.— P. trifolii. ingly Septate, subfasciculate, olivaceous; co- 
ter or a. nidia ovoid or subclavate, continuous or 
1-septate, acrogenous, solitary or paired. 

In part=Venturia and Phyllachora. ' 

Over forty species, several pathogenic. 

F. fraxini Aderh. on Ash.=V. fraxini. See p. 255. 

F. saliciperdum (All. & Pub.) Land, on Salix=V. chlorospora. 
See p. 255. 

F. cerasi (Rab.) Sacc. on cherry, peach, =V. cerasi. See p. 255. 




THE FUNGI WHICH CAUSE PLANT DISEASE 607 

F. pirinum (Lib.) Fcl. on pear=V. pirinia. See p. 253. 

F. dendriticum (Wal.) Fcl. on pomaceous fruits=V. inscqualis. 
See p. 253. 

F. orbiculatum Thiim on Sorbus=V. insequalis var. cinerascens. 
See p. 255. 

F. depressum (B. & Br.) Sacc. on Umbellifer2e=Phyllachora. 

F. betulae Aderh. on birch =V. ditricha. See p. 255. 

F. tremulae Fr. on aspen =V. tremulse. See p. 255. 

F. fagopyri Oud. is found on buckwheat; 

F. lini Sor. on Linum. 

F. eriobotryae Cav. attacks leaves of Eriobotrys.^ 

F. destruens Pk. 

Conidiophores short, 20-50 /x, fasciculate, continuous or 1 
to 2-septate, basally, colored, clusters slightly olive-green; conidia 
acrogenous, continuous or 1-septate, subcatenulate, ellipsoid 
to oblong, colored, 7-20 x 5-7 n. 

On oats. 

F. effusum Wint.^^s 

Spots minute, rounded, rarely effused, confluent, smoky; coni- 
diophores erect, simple or slightly branched, septate, torulose, 
brownish, lighter above, 100-140 x 4 /i; conidia oblong fusoid to 
rhomboid, continuous or uniseptate, light fuscous, subtruncate, 
17-24 X 5.5-7 M- 

It constitutes the pecan scab affecting the leaves, stems and nuts. 

F. vanillae Zim. is on vanilla. 

An undetermined species is the cause of a black canker of Hevea. 

Passalora Fries & Montaigne (p. 602) 

Conidiophores filiform, intricate multiseptate, olive; conidia 
oblong to fusoid, acrogenous. 

A small genus quite similar to Fusicladium except for the pluri- 
septate conidiophores. 

P. bacilligera M. & F. and P. microsperma Fcl. occur on Alnus. 

Scolecotrichum Kunze & Schmidt (p. 602) 

Conidiophores short, subfasciculate, olive; conidia oblong or 
ovate, pleurogenous or acrogenous. 

A genus of some thirty species very similar to Fusicladium. 



608 



THE FUNGI WHICH CAUSE PLANT DISEASE 



S. graminis Fcl. 

Spots foliicolous, elongate, ochraceous; conidiophores densely 
fasciculate, filiform, simple, sinuose, 90-100 x 
6-8 n, subcontinuous; conidia fusoid-obclavate, 
35-45 X 8-10 n, uniseptate, olive-brown. 

It is common, causing leaf spots on grasses, 
especially on Avena and Phleum. It is de- 
scribed on the latter by Trelease.^^^ The my- 
celium collects below the stomata and pushes 
its tuft of hyphae through them. 

S. melophthorum P. & D, parasitizes melons 
and cucumbers in France; ^°° 
S. fraxini Pass, is on ash. 
S. iridis F. & R. is on Iris; 
S. musae on banana. 
S. avense Erik, is on oats. 




Fig. 409. — S. grami 
nis. After Sac 
cardo. 



Dematiaceae-Phragmosporae (p. 594) 

Conidia 2 to many-celled, dark, rarely light or hyaline, ovoid to 
cylindric or vermicular. 



Key to Genera of Dematiaceae-Phragmosporae 

Fertile hyphae very short or little different 
from the conidia 
Conidia not in chains 
Conidia muticate 
Conidia united at base, fasciculate, 

cylindric 1. Cryptocoryneum. 

Conidia separate 

Conidia straight ovoid to cylindric 

Conidia solitary 2. Clasterosporium, p. 609. 

Conidia in bundles 3. Stigmina, p. 610. 

Conidia fusoid-falcate 4. Fusariella. 

Conidia cuspidate or setose 

Hyphse dichotomous and broadened 

at apex 5. Urosporium. 

Hyphae not dichotomous or broad- 
ened 6. Ceratophorum, p. 610. 

Conidia in chains 



THE FUNGI WHICH CAUSE PLANT DISEASE 



609 



Conidia not connected by isthmi 7. Septonema. 

Conidia connected by isthmi 8. Polydesmus. 

Fertile hyphse distinctly different from 
the conidia 
Conidia soUtary or nearly so, acrog- 
enous for the most part 

Conidia muticate 9. Helminthospora. 

Conidia echinulate 10. Heterosporium, p. 610. 

Conidia smooth 

Hyphse creeping, radiate 11. Ophiotrichum. 

Hyphae short, ascending or 
erect, conidia ovoid to 

oblong 12. Napicladium, p. 611. 

Hyphse longer, rigid; conidia 
ovoid to elongate 

Conidia ovoid 13. Brachysporium. 

Conidia elongate 14. Helminthosporium, p. 611. 

Hyphae flexuous, pannose. ... 15. Drepanospora. 

Conidia 1 to 3-ciliate at apex 16. Camposporium. 

Conidia verticillate or capitate 
Hyphse dark 
Conidia acrogenous, forming a 
head 

Hyphse simple 17. Acrothecium. 

Hyphae branched at the apex. 18. Atractina. 
Conidia pleurogenous, some- 
what verticillate 
Hyphse rostrate and naked at 

apex 19. Rhynchomyces. 

Hyphffi not rostrate at apex. . 20. Spondylocladium, p. 614. 
Hyphse hyaline or bright colored, 

apex denticulate 21. Neomichelia. 

Conidia catenulate as a rule 

Conidia arising from the interior of 

the hyphae IV. Sporoschismeae. 

Conidia arising from the apex, 

sometimes solitary V. Dendryphieae, p. 615. 

Clasterosporium Schweinitz (p. 608) 

Hyphse creeping, here and there swollen, erect, bearing 2 to 
several-septate, solitary, apical conidia. 




610 THE FUNGI WHICH CAUSE PLANT DISEASE 

A genus of some seventy-five species. 

C. glomerulosum Sacc. on Juniperus leaves is often reported 
as Sporodesmium glomerulosum. 

C. carpophilum (Lev.) Aderh.^^' ^°^' ^°^' '^^ Aderhold by inocu- 
lations, properly controlled, showed this fungus capable of causing 
gummosis of prunaceous hosts though C. herbarium did not do so. 
Effuse, hyphse simple or short-branched, densely aggregated, 
septate, conidia elongate-fusoid, obtuse, 4 to 5-septate, slightly con- 
stricted at the septa. It is commonly seen as 
the cause of a brown spot on peaches. Spores 
do not appear in the young spots but are found 
sparingly in older bro^vn areas. 

Pure* culture inoculations by Stewart ^^ on 
peach twigs resulted in blackening and gum- 

FiQ. 410.— Stigmina. mosis. 

After Saccardo. ^ amygdalearum (Pass.) Sacc. is also de- 

scribed on rosaceous hosts. It is perhaps identical with C. car- 
pophilum and may be connected with Pleospora vulgaris.^^^ 

C. putrefaciens (Fcl.) Sacc. causes spots on leaves of the sugar- 
beet. 

Stigmina Saccardo (p. 608) 

Hyphse epiphyllous; conidiophores very short or obsolete; coni- 
dia ovate or elongate, 3 or more-celled, aggregated. 
S. briosiana Far. causes disease of apricots in Europe. 

Ceratophorum Saccardo (p. 608) 

Hyphae creeping, scant; conidiophores short, erect; conidia 
fusoid or cylindric, 2 to many-septate, dark or reddish-brown. 

A small genus. 

C. setosum Kirch, is found on leaves and shoots of young plants 
of Cytisus, etc., in greenhouses; ^°^ 

C. ulmicolum E. & K. on Ulmus leaves. 

Heterosporium Klotzsch (p. 609) 

HyphsB subcespitose, smoothish, often branched; conidia oblong, 
2 to several-septate, smoothish to granular or echinulate. 
A genus of forty species or more. 



THE FUNGI WHICH CAUSE PLANT DISEASE 611 

H. echinulatum (Berk.) Cke.-^- -°' 

Spots gregarious, on fuscous areas; conidiophores fasciculate 
from a stromatic base, 150-200 x 8 /x, rarely shorter, flexuose- 
nodose, fuliginous; conidia at the nodes, oblong-cylindric, rounded 
at the ends, 2 to 3-septate, 40-50 x 15-lG /i, slightly constricted, 
roughened, brownish. 

It causes a destructive mold on carnation leaves and stems. The 
first epidemic was noted by Sorauer in Berlin in 1883. 

H. gracile (Wal.) Sacc. was determined to be the cause of dis- 
ease of Iris, Narcissus and other Monocotyledons. ^°^ 

H. variable Cke.^oe 

Conidiophores flexuose, slender, more or less nodulose at the 
septa; conidia cylindric oblong, 2 to 4-septate, minutely warted, 
20-25 X 7-10 ju, pale olive. On spinach. 

Other parasitic species are: 

H. ornithogali Klotz. on Liliaceae; 

H. laricis C. & M. on larch leaves; 

H. auriculi ]Mas. on cultivated Auricula; 

H. syringae Oud. on lilac leaves.** 

H. minutulum C. & M. causes disease of hops. 

Napicladium von Thiimen (p. 609) 

Conidiophores short, subfasciculate, smoothish; conidia acroge- 
nous, solitary, large, oblong, 2 to many-septate, smoothish. 

A small genus. 

N. janseanum Rac. is on rice. 

N. soraueri is a form of Venturia inaequalis with somewhat 
atypical napiform spores. See p. 253. 

Helminthosporium Link (p. 609) 

Conidiophores erect, rigid, subsimple, fuscous; conidia fusoid 
to elongate-clavate or cylindric, pluriseptate, fuscous, smooth. 

In part=Pleospora. See p. 259. 

About two hundred species; several are important pathogens, 
others saprophytes. 

The species show biologic differentiation into races similar to 



612 



THE FUNGI WHICH CAUSE PLANT DISEASE 



that exhibited in the Erysiphacese, though morphologically they 
may be inseparable. 




Fig. 411. — Helminthosporium gramineum. Conidio- 
phoree and spores. After Eling. 

H. gramineum (Rab.) Erik, on grasses =Peleospora gramineum. 
See p. 261. 
H. trichostoma=Pleospora trichostoma. See p. 260. 




Fig. 412. — Helminthosporium teres. Conidiophores 
and spores. After King. 

H. teres Sacc. 

Spots oblong, olive, amphigenous; conidiophores fasciculate, 
often crooked and nodulose, septate, brown, 100-130 x 12 )u; 



THE FUNGI WHICH CAUSE PLANT DISEASE 



613 



conidia acrogenous, straight, cylindrical, ends rounded, 4 to 5- 
septate, not constricted, dark olive-brown, 100-115 x 14- 
18 ju. On oats and barley. 

H. avenae Ei. 

Similar to H. teres, but the conidiophores scattered, 150-200 x 
9-12 fx, septate, brown; conidia cylindric, brownish, 4 to 6-septate, 
80-100 X 15-16 M. On oats. 

The conidia of the two last species infect grains and seedlings. 
The conidia spread the disease from the early infection centers 
to other parts of the plants but the mycelium remains local. 

H. bromi Died, on Bromus=Pleospora bromi, see p. 261. 

H. tritici-repentis Died.=Pleospora tritici-repentis, see p. 262. 

H. sativum (P.) K. & B.^^^ 

Mycelium branched, septate; conidiophores fasciculate, fuscous, 
brown, septate, 8-10 /x wide, sometimes swollen between the 
septa; conidia solitary, apical, dark brown, 6 to 11-septate, 105- 
130 X 15-20 M. 

The cause of a destructive late blight of barley from Iowa to 
Saskatchewan. The disease manifests itself by dark colored, 
elongate spots on the leaves. 
It also occurs on the glumes 
and spikelets, sometimes even 
penetrating the grains. 

H. sorokinianum Sacc. is re- 
ported on wheat and rye in 
Russia; 

H. tritici Hen. on wheat in 
Africa; H. sigmoideum Cav. 
on rice in Italy; while several 
species are recorded on bam- 
boo. 

H. turcinum Pass. 

Spots, large, dry, brownish; conidiophores, gregarious to fascicu- 
late, septate, 150-180 x 6-9 n, pale olive, apex almost hyaline, 
often nodulose; conidia spindle-shaped, acute, 5 to 8-septate, 
pale olive, 80-140 x 20-26 /x. 

It produces spots on corn and sorghum in Europe and America. 

H. inconspicuum C. & E.^^- 308-3io 




Fig. 413. — Helminthosporium sativum 
from barley, spores and conidiophores. 
After King. 




614 THE FUNGI WHICH CAUSE PLANT DISEASE 

Conidiophores elongate, septate, nodose, pale brown; conidia 
lanceolate, 3 to 5-septate, 80-120 x 20 ju, smooth. 

It has been reported on sweet corn from Long Island by Stewart. 
H. gramineum, H. turcinum and H. incon- 
spicuum are closely related, possibly identical. 

Johnson ^^° concludes that H. gramineum with 
its ascosporic stage includes Piricularia grizea, 
P. oryzse, Helminthsporium oryzae and H. tur- 
cinum. 
H. inaequalis Sh. 

Sterile hyphse effuse, much branched, dark 
brown; conidiophores erect, septate, variable 
in length, 6-8 ju in diameter; conidia both ter- 
FiG. 414.— Helmin- ^\^q\ and lateral, more or less curved, 3 to 

thosporium in- ' ' 

sequalis. After 5-celled, thick- walled, browTi, 23-32 x 11-14 fx. 

Shear. ^ , 

On cranberry. 

H. heveae Fetch, is on Para rubber; 

H. theae Bernard on tea in India; 

H. iberidis Poll, on Iberis and H. lunariae Poll, on Lunaria, both 

in Italy. 

Spondylocladium Martius (p. 609) 

Hyphse creeping, septate; conidiophores erect, simple, rigid; 
conidia v^rticillate, fusoid, usually 3-celled, brownish. 
A small genus. 

22 

S. atrovirens Harz. 

Conidiophores solitary or clustered, cylindric, septate, dingy, 
olive or brownish, up to 400 /x high; conidia elongate, ovate, apex 
narrowed, 5 to 7-septate, concolorous with the conid- 
iophores, 30-50 X 6-9 IX. 

On potatoes this fungus causes blackish to olive 
spots soon depressed, 2-3 cm. across, which are 
beset with small black sclerotia and followed by dry 
rot. According to Appel & Laubert ^^^ the sclerotia 
develop whorls of conidiophores. The species is atrovirens! 
said to occur in the British Isles, the Continent After Massee. 
and in America.^^- Its sterile mycelium has been described under 
the name Phellomyces.^^^ 




THE FUNGI WHICH CAUSE PLANT DISEASE 615 



Dendryphium Wallroth (p. 609) 

Hyphse creeping or obsolete; conidiophores erect, with short 
apical brandies; conidia cylindric, 2 to many-septate, catenulate, 
brown. 

Some thirty or more species. 

D. comosumWal. is the cause of a cucumber leaf spot in England. 

Dematiaceae-Dictyosporae (p. 594) 
Conidia dark, rarely light, muriform, globose to oblong. 

Key to Genera of Dematiaceae-Dictyosporae. 

Hyphae very short or scarcely different from 

the conidia I. Micronemeae. 

Conidia not in chains 
Conidia not appendaged 

Conidia irregularly muriform or 
sarciniform 
Conidia with a conic point at each 

side 1. Oncopodium. 

Conidia without conic points 
Conidia globose to oblong 
Conidia ovoid to oblong, loose 2. Sporodesmium,p. 616. 
Conidia globose to ovoid, ag- 
gregated 3. Stigmella. 

Conidia sarcinseform, often co- 

alescent 4. Coniothecium, p. 617. 

Conidia as if composed of parallel 
chains of cells 
Chains of conidia never separat- 
ing 5. Dictyosporium. 

Chains of conidia separating 6. Speira. 

Conidia corniculate at apex 7. Tetraploa. 

Conidia in chains, often asperate or with 

isthmi 8. Sirodesmium. 

Hyphse distinctly different from the conidia II. Macronemeae. 
Conidia of the same form ' 

Conidia not in chains or capitate 
Conidia bearing little conidia on their 
- surfaces 9. Xenosporium. 



616 THE FUNGI WHICH CAUSE PLANT DISEASE 

Conidia single 
Hyphse alike 

Conidia cruciate-divided, verm- 
cose 10. Tetracoccosporium. 

Conidia muriform, typically 
smooth 

Hyphse decumbent 11. Stemphylium, p. 617. 

Hyphse erect or ascending 
Conidia globose, pleuro- 
gynous 
Conidia around the apex 

of the hyphse 12. Coccosporium. 

Conidia conglobate 

around the base 13. Trichaeguia. 

Conidia ovoid to oblong, 
mostly acrogenous 
Conidiophores somewhat 

lax, colored 14. Macrosporium, p. 618. 

Conidiophores rigid, very 

dark 15. Mystrosporium, p. 620. 

Hyphse of two kinds, longer 

sterile, shorter fertile 16. Septosporium, p. 620. 

Conidia capitate 17. Dactylosporium. 

Conidia catenulate 
Hyphse velvety, erect, subsimple; 

conidia caudate 18. Alternaria, p. 621. 

Hyphse crustose, various; conidia 2- 
celled; conidia-like ganglia sar- 

cinseform 19. Fumago, p. 624. 

Conidia of two forms, dark sarcinseform 

and subhyaline falcate 20. Sarcinella, p. 625. 

Sporodesmium Link.^^^ (p. 615) 

Mycelium and conidiophores poorly developed; conidia ovoid 
oblong, subsessile or short-stalked, rather large, clathrate-septate, 
fuligineus. 

Over eighty species. 

S. piriforme Cda. on oranges =Pleospora hesperidearum, 
p. 260. 

S. exitiosum Ktihn on crucifers=Leptosphseria napi, p. 258. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



617 



S. exitiosum var. solani Schenck is reported as the cause of a 
potato disease. 

S. solani-varians Vanha is the cause of 
potato disease in Europe, the foliage bearing 
brown spots and finally dying in a manner 
resembling death caused l)y Phytophthora. 
Cladosporium and pycnidial forms are said 
to exist. 

S. mucosum Sacc. was reported by Ader- 
holt on cucumber fruit and leaves causing 
disease. 

S. scorzonerae Aderh. causes a salsify 
stem and leaf disease. ^^'* 

Other parasitic species are: 

S. melongena Thiim. on egg plant; 

S. dolichopus Pass, on potato leaves in 
Italy; 

S. ignobile Karst. on asparagus; 

S. putrefaciens Fcl. on beet; 

S. brassicae Mas. on Brassica in Bengal. 




Fig. 416. — Sporodesmium 
antiquum. After Sac- 
cardo. 



Coniothecium Corda (p. 615) 

Hyphse obsolete or poorly developed; conidia 
gemmiform in origin, variously septate. 

Over fifty species of very simple parasitic or 
saprophytic fungi. 

C. chomatosporum Cda. resembling apple 
scab in its effect is noted as common in Tas- 
mania^^^ and Australia. "^^^ 

Stemphylium Walroth (p. 616) 

Conidiophores decumbent, intricately 
branched, hyaline or smoky; conidia acrogenous, 
ovoid to subglobose, 2 to many-muriform- 
septate, fuligineus. 

Over thirty species. 
S. ericoctonum B. & deB. is parasitic on Erica in green-houses. 




Fig. 417.— Stemphy. 
lium. After Sac 
cardo. 



618 THE FUNGI WHICH CAUSE PLANT DISEASE 

S. citri Pa. & Ch.^^ 

Vegetative mycelium long, hyaline, becoming dark, 4 ju in 
diameter, septate; conidiophores short; conidia dark ])rown, sub- 
globose to oblong, apiculate, irregularly muriform, 20-30 x 12- 
15 n, usually in chains of three. 

This was found associated with an end-rot of oranges from 
Arizona. Inoculated in pure culture in oranges the fungus de- 
veloped well. It is perhaps the cause of the disease. 

S. tritici Pa. 

Hyphse irregularly branched; conidiophores closely septate, 
4-5 fjL in diameter; conidia catenulate, irregular, usually clavate, 
constricted slightly at the septa, 24-35 x 12-15 n, vermiculate, 
fuligineus, isthmus short, 3-4 n in diameter. It is described as 
the cause of floret sterility of wheat. ' 

Macrosporium Fries (p. 616) 

Conidiophores fasciculate, erect or not, more or less branched* 
colored; conidia usually apical, elongate or globose, dark-colored. 

In part=Pleospora. See p. 259. 

About one hundred eighty species, many of them saprophytes 
while others are important pathogens. 

M. commune Rab.=M. sarcinula parasiticum Thiim. on vari- 
ous grasses =Pleospora herbarium. ^^^' ^^^ See p. 260. 

This is reported by Thaxter ^^^ as the common black mold which 
follows Peronospora on the onion and which occurs often also on 
onions no^ so diseased, being especially common on the seed stalks. 
It is usually associated with injured plants and may be important 
only as a wound parasite. 

M'. porri E.^^^ 

Effuse, fuligineus; hyphse short, simple, subfasciculate; conidia 
elongate-clavate, basally attenuate, multiseptate, 150-180 x 
12-20 M- 

It is common on seed onions, less common on market onions. 
The dark mycelium penetrates the host in all directions and finally 
produces stromata below the stomata and sends up short hyphis. 

M. alliorum C. & M. is also on onion; ^^ 

M. hurculeum E. & M. 

Amphigenous on rounded, grey spots; conidiophores erect, ces- 



THE FUNGI WHICH CAUSE PLANT DISEASE 619 

pitose, flexuose, brown, few septate, 70-80 x 5 m; conidia brown, 
multiseptate, clavate, 200-225 x 21-26 /x- 

It causes leaf spots on turnips, horse radish and other crucifers. 

M. brassicae Berk. 

Mycelium inconspicuous, conidia clavate, antennaiform, 5 to 
11-septate, 50-60 x 12-14 ju. 

It is a common cause of black mold on cabbage, collards and 
other crucifers. 

M. ramulosum Sacc. is on celery. 

M. catalpae E. & M. ^^ 

On brownish spots; conidiophores brown, curved, nodose, 8 to 
12-septate, erect, amphigenous, 90-135 x 6 m; conidia brown, 
obovate to pyriform, submuriform, 27-51 x 15-27 fx. 

Producing leaf spots on Catalpa in company with Phyllosticta 
eatalpse. 

M. nobile Vize. is on Dianthus. 

M. iridis C. and E. and M. aductum Mas. are on iris; 

M. cheiranthi (Lib.) Fr. on Cheiranthus. 

M. tabacinum E. & E.^^® causes thin, white amphigenous spots, 
2-3 mm. with a narrow dark border; conidiophores effused, 35-45 x 
3-4 n, septate and torulose above; conidia obovate, 15-25 x 10- 
12 n, sessile or short stipitate, usually 3-septate. 

It is reported to cause white leaf spots on tobacco. 

M. longipes E. & E. 

On concentric, rusty brown, amphigenous spots, 3 to 5 mm. in 
diameter; conidiophores effused, amphigenous, slender, 40-70 x 
3-4 n, septate, often contracted at the septa, erect and more or 
less torulose above; conidia clavate, 40-50 x 15-20 m, 3 to 
7-septate, attenuate below into a distinct stipe. On tobacco. 

M. sarciniforme Cav. is reported by Walkoff ^^^ on red clover 
in Germany where it causes the leaves to dry and die. 

M. nigricanthium Atk.^-^ 

Amphigenous; condiophores subfasciculate or scattered nodose, 
septate, olive-brown, 50-140 x 6-7 ju; conidia olive-brown, con- 
stricted about the middle, rostrate at one side of the apex, 18- 
22 x 36-50 fjL. On cotton. 

M. cucumerinum E. & E.^-^'^-^ 

Epiphyllous on orbicular, subconfluent, brownish spots, 3-4 



620 



THE FUNGI WHICH CAUSE PLANT DISEASE 




Fig. 418. — Macio- 
sporium cucumer- 
inum on cante- 
loupe. After 
Chester. 



mm. in diameter; conidiophores fasciculate or 
solitary, subgeniculate, 1 to 3-septate, 35-50 x 
5-6 /x; conidia clavate, slender-stipitate, 3 to 
8-septate, somewhat constricted, submuriform, 
30-75 X 15-25 fj.; pedicel 25-35 n long. 

On leaves, stems and fruits of cantaloupes. 

M. cladosporioides Desm. is on beet, lettuce, 
onion and many other hosts. 

M. verrucosum Lutz. occurs on cacao; 

M. gramineum Cke.^-^ on sugar cane. 

M. uvarum Thtim. is reported on Vitis; 

M. violae Poll, on violets in Italy; 

M. saponariae Pk. on Saponaria. 

M. macalpinianum S. &. Sy. is injurious to 
Pelargonium. 



Mystrosporium Corda (p. 616) 

Conidiophores simple or sparingly branched, short, septate, 
fuscous, rigid; conidia elliptic, subglobose or oblong, pluriseptate, 
muriform, dark, usually solitary, acrogenous. 

Some twenty species. 

M. abrodens Nebr. is described as the cause of a very serious 
grain disease in France. 

M. aductum Mas. injures Iris bulbs; 

M. alliorum Berk, forms dark spots on onion. 



Septosporium Cda. (p. 616) 

Conidiophores short, intermixed with longer sterile hyphae; 
conidia ovoid to pyriform, fuscous. 

A small genus. 

S. heterosporium E. & G. 

Spots scattered, confluent or not, rusty brown, 0.5-1 cm. in 
diameter, conidiophores hypophyllous, fasciculate from the sto- 
mata; conidia variable, oblong cylindric, constricted at the 
septa, 20-40 x 5-7 fx, separating into gemmse. 

Reported in 1888 ^- on the wild grape in California. 



THE FUNGI WHICH CAUSE PLANT DISEASE 621 



Alternaria Nees. (p. 616) 

Conidiophores fasciculate, erect, sub-simple, short; conidia 
clavate-lageniform, septate, muriform, catenulate. 

In part=Pleospora. See p. 259. 

Some thirty or more species, many of pronounced economic im- 
portance. 

A. sp. on Tropoeolum=Pleospora tropoeoli. See p. 260. 

A. trichostoma Died, on barley =Pleospora trichostoma. See 
p. 260. 

A. forsythiae Harter.^^^ 

Hyphae cespitose, amphigenous; spot concentric zonate: conidia 
18-60 X 10 X 16.5 M- 

It causes subcircular leaf spots on cultivated Forsythia. 

A. brassicae (Berk.) Sacc. 

Conidiophores short, continuous, short-branched, apically 
equal, conidia elongate, fusoid, clavate, 60-80 x 14-18 n, 6 to 8- 
muriform-septate, olivaceous. 
On crucifers. 

A. brassicae (Berk.) Sacc. 
var. phaseoli Brun. occurs on 
beans in Italy. 

A. cucurbitae Let.^-^' ^-^ may 
be identical with A. brassicae. 

It was noted by Thax- 
ter in Connecticut causing 

blight of melons. The black Fig. 419. — A. violae, germinating spores. 
, , . . • i 1 11 After Dorsett. 

mold IS copious m the older 

circular spots. Pure cultures were obtained and successful in- 
oculations were made on normal uninjured melon leaves. 

It is also reported by Selby^-^ as the probable cause of muskmelon 
leaf spots in Ohio, and it is a common source of troubles on various 
cruciferous hosts. 

A. tenuis Nees.^^ is reported by Behrens on tobacco seedlings. 

A. violae G. & D. '^' 

Conidiophores erect, pale-olive, septate, simple, 25-30 x 4 ^t, 
conidia in chains at or near the apex of the conidiophore, clavately 




622 



THE FUNGI WHICH CAUSE PLANT DISEASE 



flask-shaped, strongly constricted at the septa, olive, 40-60 x 
10-17 M- 

Circular leaf-spots are produced on violets. Spores are found on 
the spots only when conditions are most favorable, i. e., in a humid 
air. The parasitism of the fungus was demonstrated by inocula- 
tion with spores on living leaves in distilled water. 

A. panax Whet.-^^ 

Spots amphigenous, circular, becoming dingy white with a 




Fig. 42U.— Alter- 
n a r i a. Spores 
and spore-bear- 
ing stalks. Af- 
ter van Hook. 




Fig. 421. — A. clianthi. 3, Mycelium showing 
branching and septation. 4< Showing my- 
celium below stoma and hyphse emerging 
through the stoma. 5, Showing catenu- 
late spores as borne upon hyphse. 6, Spores 
showing shape, septation and catenulation. 
7, A young cluster of hyphse. 5, An older 
cluster of hyphse. After Stevens and Hall. 



reddish-brown margin, covering half the leaflet or less; hyphse 
-brown, septate, 5-7 (x in diameter; conidiophores erect, tufted, 
somewhat irregular, especially at the tips, brown, septate, 100- 
120 X 5-6 fj-; conidia brown, in chains of 5 or 6, elliptic to oblong, 
45-65 X 15-20 /x- 

On ginseng causing leaf blight. 

A. dianthi S. & B..^^^ 

Spots epiphyllous, ashen-white, definite, circular. Conidiophores 
cespitose from stomata, amphigenous, dark-brown, 1 to 4-septate, 
erect, 1-25 from a stoma; conidia 26-123 x 10-20 fx, clavate. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



623 



tapering, obtuse, basally dark-brown, slightly constricted at the 

septa, 5 to 9 times cross-septate and 0-5 times longitudinally 

septate. 

It causes injury on carnation leaves and stems. 

A. solani (E. & M.) Jones & Grout. '''• '''• ^''-^" 

Spots brown, circular to elliptic, concentrically zonate, amphige- 

nous, irregularly scattered over the leaf surface; mycelium 




Fig. 422. — A. solani, 2, spores germinating and penetrating the living 
potato leaf; 5, showing catenulation of spores. After Jones. 

light-brown; conidiophores erect, septate, 50-90 x 8-9 ix; conidia 
obclavate, brown, 145-370 x 16-18 /x with 5 to 10 transverse 
septa, longitudinal septa few, conidia terminating in a very long 
hyaline, septate beak Y2 the length of the conidium or longer. 

It causes early blight, a leaf spot disease of potatoes and toma- 
toes,^^^ and is widely prevalent. It was first described in 1882 in 
America but is now known to be widely destructive.^^'' On potatoes 
it was first recorded by Galloway in 1891. In 1891 also Ches- 
ter ^^^ and Galloway ^^^ proved its pathogenicity by inoculations on 



624 THE FUNGI WHICH CAUSE PLANT DISEASE 

tomato and potato, the spots appeared in eight or ten days after 
inoculation. Jones, using pure cultures, confirmed the conclu- 
sions of Chester and Galloway, the disease spots appearing as early 
as the third to fifth day after inoculation on vigorous uninjured 
leaves. The mycelium grows luxuriantly within the leaf but spores 
do not usually form until after the death of the supporting tissues 
when the conidiophores emerge through the stomata or by ruptur- 
ing the epidermis. Often no spores are formed and rarely are 
many present. The mycelium may live a year or more and resume 
sporulation the following season. 

A. fasciculata (C. & E.) Jones & Grout.^^^' ^^^' ^^^' ^^^ 

Conidiophores light or dark-brown, becoming almost black, 
darker than the vegetative hyphae but like them echinulate, 
30-40 X 4-5 n; conidia concolorous with the conidiophores, 35-66 
X 16-20 M, obclavate, 3 to 6 times cross-septate, 1 to 2 longi- 
tudinal septa, apical cell hyaline. 

This fungus is associated as a saprophyte with the blossom- 
end-rot of tomatoes and also causes a serious decay of the ripened 
fruit. The literature of the disease is rather voluminous and con- 
tains a number of synonyms, among them Macrosporium tomato. 
M. lycopersici, M. rugosa, M. fasciculata. Alternaria solani has 
also been credited with this disease and indeed the two species 
may be identical. ^^^ 

A. fici Far. is on figs; 

A. tabacinum Hori on tobacco;" 

A. vitis Cav. on Vitis. 

An undetermined Alternaria accompanied by a Macrosporium 
was constantly found in Nevadillo bianco olives which were 
shrivelled, particularly at the apex. 

These fungi were regarded as the cause of the disease.^*^ 

Fumago Persoon (p. 616) 

Hyphae decumbent, intricate, frequently pseudo-stromatic, 
black; conidiophores, erect, branched; conidia ovoid, oblong or 
sarcinseform, 1 to 2-septate. 

A small genus, chiefly conidial forms of Capnodium and Meliola. 
See pp. 192, 193. 



THE FUNGI WHICH CAUSE PLANT DISEASE 625 

F. camelliae Cat. on various hosts =Meliola camellise. See 
p. 193. 

Sarcinella Saccardo (p. 616) 

Hyphaj decumbent, septate, branched, dark; conidiophores 
much reduced; conidia of two kinds: 1, dark packet-like; 2, sub- 
hyaline falcate. Both are intermixed. 

A small genus chiefly conidial forms of Dimerosporium. See 
p. 190. 

S. heterospora Sacc. on various hosts = Dimerosporium pul- 
chrum. See p. 191. 

Dematiaceae-Scolecosporae (p. 594) 

Conidia dark or subhyaline, vermiform or filamentose, multi- 
septate. 
There is only one genus. 

Cercospora Fries 

Conidiophores variable, almost obsolete or well developed, 
simple or branched; conidia vermiform or filiform, straight or 
curved, multiseptate, subhyaline to dark. 

In part =Mycosph8erella. See p. 243. 

The genus is a very large one, some seven hundred species, and 
contains very many aggressive, important parasites, chiefly causing 
leaf spotting. The spots are often blanched and are rendered 
ashen colored in the centers by the presence of the dark hyphse. 
The hyphse are usually geniculate at the point of spore produc- 
tion. Fig. 427, and thus old hyphse bear traces of spores previously 
borne. 

C. cerasella Sacc. on cherries =Mycosphserella cerasella. See 
p. 245. 

C. gossypina Cke. on cotton =Mycosphserella gossypina. See 
p. 248. 

C. circumscissa Sacc. 

Spots amphigenous, circular, pallid, dry, deciduous; conidio- 
phores fasciculate, nodulose, brownish, simple; conidia acicular, 
narrowed apically, attenuate, tinged brown, 50 x 3.5-4 /x. 



626 THE FUNGI WHICH CAUSE PLANT DISEASE 

On various species of Prunus this causes leaf holes. 
It is reported as especially serious on the almond.^^^ 
C. bolleana (Thum.) Sacc. 

Hypophyllous, spots subfuscous to olivaceous; conidiophores 
fasciculate, filiform, 50-80 x 5-6 n, non-septate, fuscous; conidia 
terete, fusoid, 35-40 x 7-8 n, apically obtuse, somewhat con- 
stricted, 1 to 5-septate, olive-green. 
On figs causing leaf spotting.^*^ 
C. viticola (Ces.) Sacc. 

Spots amphigenous, subcircular to irregular, 2-10 mm. in 
diameter, ochraceous, emarginate; conidiophores erect, densely 
fasciculate, filiform, septate, 50-200 x 4-5 fx, 
straight, somewhat denticulate, ochraceous; 
conidia elongate-obclavate, somewhat at- 
tenuate, 3 to 4-septate, 50-70 x 7-8 n, olive- 
brown. ^^^ 

It is apparently an unimportant parasite 
on grape leaves. 

C. rubi Sacc. is on Rubus; 
C. fumosa Pass, on leaves of Citrus fruits. 
C. moricola Cke. is common on mulberry; 
C. musae Zimm. on banana leaves in 
Java. 

C. roesleri Sacc. occurs in Europe, causing 

Fig. 423.— C. concors. , ^ • • ^ x, 

6. Hyphce emerging ' late uijury to the grape. 

through a stoma and p ancnilata Wini- 113 

twining about hair. ^' anguiata vvmt. 

After Jones and Spots roundish, angulats, whitish to cine- 

Pomeroy. • i ^ o • t 

reous, margined, 1-3 mm. m diameter, often 
confluent; conidiophores hypophyllous, fasciculate, erect, straight 
or only slightly flexuose, simple, brownish, few septate, 78-105 x 
5 /i; conidia filiform-obclavate, long attenuate, hyaline, 7 to 16- 
septate, 80-170 x 3.5 /i. 

On the currant. 

C. oryzae Miy.^^ is on rice in Japan. 

C. concors (Casp.) Sacc.^^^' ^^^ 

Spots amphigenous, pale above, whitish beneath, rounded, in- 
definite; conidiophores fasciculate or single from the stomata, 
erect, brown, septate, simple, 40-80 n high; conidia single, 




THE FUNGI WHICH CAUSE PLANT DISEASE 



627 



apically variable in form, ovate to elongate, curved, 1 to 5-septate, 
subhyaline, 15-90 x 4-6 jx. 

In America this potato parasite was noted in Vermont in 1905 
and study of herbarium material revealed two earlier collections. 
In Germany it was known in 1854 and it has been seen in many 
parts of Europe since, sometimes in epidemic form.^'*'^ 

Conidia are abundant on the spots on stalks emerging from 
the stomata. The superior and inferior hypha; differ considerably 
in length and branching. Brown bead-like chlamydospores form 
within the leaf. The mycelium is strictly intercellular. The fungus 





Fig. 424.— C. nicoti- 
anae. After Jones. 



Fig. 425. — C. nicotianse, spores germinating and 
entering stomata. After Jones. 



was studied in artificial culture by Jones & Pomeroy^'^^ and inocu- 
lations were made, diseased spots appearing about three weeks 
after inoculation by spraying with suspensions of spores. 

C. nicotianse E. & E. 

Spots amphigenous, pale, becoming white, with a narrow and in- 
conspicuous reddish border, 2-5 mm. in diameter, conidiophores 
amphigenous, tufted, brown, septate, 2 or 3-times geniculate above, 
simple or sparingly branched, septate, 75-100 x 4-5 n; conidia 
slender, slightly curved, multiseptate, 40-75 x 3-3.5 n, hya- 
line. 

On tobacco it causes leaf spots. ^-^ The sporiferous hyphae are 
abundant near the center of the disease spots. 

C. raciborskii S. & Sy. on tobacco in Java and Austraha,^^^ is a 
near relative of C. nicotianse. 



628 



THE FUNGI WHICH CAUSE PLANT DISEASE 



C. apii Fr. 

Spots amphigenous, subcircular, pale-brown, 4-6 mm. in diame 
ter, with a more or less definite elevated margin; conidiophores hy 
pophylous, light-brown, fasciculate, con- 
tinuous or 1 or 2-septate, subundulate, 
40-60 X 4-5 ju; conidia hyaline obclavate, 
or almost cylindric, 3 to 10-septate, slen- 
der, 50-80 X 4 /x. 

A serious leaf spot is produced on celery, 
parsnips, etc.^^"'^^^ 
C. beticola Sacc^^' ^52 
Spots amphigenous, brownish, purple- 
bordered, becoming ashy centered; co- 
nidiophores fasciculate, short, simple, erect, 
fiavous, 35-55 x 4-5 m; conidia elongate, 
filiform obclavate, hyaline, multiseptate, 
75-200 X 3.5-4 /x. 

This fungus, described in 1873, causes 
a very serious disease of beet producing 
spots on the leaves. It is common and de- 
structive in America and Europe. The 
conidiophores usually, though not always, 
emerge from the sto- 
mata from a few-celled 
stroma and are amphig- 
enous. They vary in 
length and septation 
with age. If in humid Fig 
atmosphere the spots 

become hoary, due to the large number of 

spores present. Each cell of the spore is 

capable of germination. The germ tubes 

infest the host through the stomata. Pure 

Fig. 427.— Fertile hy- cultures of the fungus may readily be se- 

c. ^beticoia.^^laer cured by the usual methods. Here the 

^^sga.r. mycelium produces dense matted colonies 

of deep olive color and a greenish-grey aerial growth but no 

conidia. Found also on Spinach in Texas. 





. 426.— C. apii. After 
Duggar and Bailey. 



THE FUNGI WHICH CAUSE PLANT DISEASE 629 

C. flagelliformis E. & H. 

Spots amphigcnous, indefinite, yellowish; conidia very long, 
curved, tapering. 

The cause of spinach leaf spots. 

C. citrullina Cke. 

Epiphyllous, spots orbicular, 2-4 mm. in diameter, white with a 
purple margin; conidiophores elongate, terete, pale olivaceous, 
conidia very long, attenuate above, few-septate, hyaline, 120-140 

X 3 ;U. 

The cause of leaf spots on watermelon.^^^ 

C. cucurbitae E. & E.^^ 

Spots amphigenous, rounded, subochraceous, becoming thin and 
white, 1 to 4 mm. in diameter, border slightly raised; conidiophores 
tufted, olive-brown, 70-80 x 4 ju, continuous, subgeniculate 
above, apically obtuse; conidia linear clavate, 100-120 x 3-4 ju, 
hyaline, septate. 

On cucumbers in America, associated with Phyllosticta cu- 
curbitacearum. 

C. melonis Cke. grows on cucumbers and melons in England 
and New Zealand. What is probably the same fungus has been 
set up by Giissow ^'"'^ as a new genus Corynespora. 

C. armoraciae Sacc. 

Spots amphigenous, pale; conidiophores short, simple, 30-40 
X 5 ju; conidia rod-shaped, cuspidate, 100-120 x 5 /x, hyaline, 
multiseptate. 

On horseradish. 

C. bloxami B. & Br. occurs on Brassica. 

C. personata (B. & C.) E. 

Spots hypophyllous, small, brown, orbicular, 2-4 mm. or more 
in diameter; conidiophores densely tufted, short, brown, con- 
tinuous; conidia clavate, pale-brown, about 3 to 4-septate, 30- 
50 X 5-6 fx. 

On the peanut in the Southern United States and West Indies. ^^^ 

C. cruenta Sacc. 

Spots amphigenous, indefinite, reddish ; conidiophores, subfasci- 
culate, simple, subdenticulate, light olivaceous; conidia obclavate, 
curved, 60-80 x 4 /i, subacute, 6 to 7-septate, hyaline or oliva- 
ceous. 



630 THE FUNGI WHICH CAUSE PLANT DISEASE 

On cowpea and bean in America. Usually causing but slight 
damage. 

C. vignae Rac. (not E. & E.) is described as injurious to the 
cowpea in Java.^'''* 

C. medicaginis E. & E. 

Spots amphigenous, smoky to black, 0.5-5 mm. in diameter, 
orbicular, indefinite; conidiophores subhy aline, becoming brown- 
ish, continuous, geniculate, 35-45 x 4-5 n; conidia cylindric- 
fusoid, 3 to 6-septatc, 40-60 x3 fx. 

On alfalfa and crimson clover.^''^ 

C. ariminensis Br. & Cav. is found on sulla leaves; 

C. saccharii Br. d. H. C. longipes Butler, C. acerosum D. 
& H., C. vaginae and C. kopkei Krug. are on sugar-cane. 

C. capparidis Sacc. is found on caper. 

C. asparagi Sacc. & C. caulicola Wint. affect asparagus. 

C. malkoffi Bubak causes an anise disease in Sadova. 

C. these v. Br. d. H. occurs on tea in India; 

C. violae Sacc. 

Spots amphigenous, rounded, bleached; conidiophores short, 
simple, greyish, 30-35 x 4 /x; conidia long and slender, rod- 
shaped, multiseptate, hyaline, 150-200 x 3.5 m- 

It produces a violet leaf spot.-^ 

C. althaeina Sacc. occurs on hollyhock. 

Spots amphigenous, brown, 2-4 mm. broad; conidiophores 
fasciculate, slender, 40 x 5 ju, few-septate, olive brown; conidia 
apical, cylindric, to obclava,te or broadly fu- 
soid, straight, 40-60 x 5 ju, apically obtuse, 
2 to 5-septate, hyaline. 
C. kellermanii Bub. 

Spots amphigenous, irregular, angular, olive- 
brown, up to 1 cm. across; conidiophores fas- 
MlflMlBJM ciculate, slender, few-septate, 150 n x 4-5 n, 

Fig. 428.— C. rosfficola. olive-brown; conidia filiform, 50-150 x 4-5 n, 

After Southworth. 5 ^^ I5_septate, straight or curved, hyaline. 

It also occurs on hollyhock and is nearly related to C. malvarum 
Sacc. 

C. rosicola Pass.^^ 

Spots ochraceous, fuscous-margined, 2-3 mm. in diameter; 




THE FUNGI WHICH CAUSE PLANT DISEASE G31 

conidiophores cespitose, small, densely gregarious, fuliginous, 
subcontinuous, 20-40 x 3-5 /x, conidia cylindric, straight, short, 
30-50 X 3.5-5 n, subfuscous, 2 to 4-septate. 

On roses. 

C. hypophylla Cav, on roses in Europe is very like the preceding 
species. 

C. omphacodes E. & H. and C. phlogina Peck, are the causes of 
rather unimportant leaf spots of cultivated phlox. 

C. neriella Sacc. is on oleander. 

C. sordida Sacc. produces leaf spots and defoliates Tecoma. 

C. angreci Roum. is on orchids; 

C. cheiranthi Sacc. on Cheiranthus. 

C. brunkii E. & G. is reported on the geranium (Pelargonium 
zonale.) 

C. resedae Fcl.^^^ 

Spots punctiform, greyish; conidiophores fasciculate, simple, 
continuous or few-septate, 50-70 x 4-5 /x, fuscous; conidia apical 
to linear, obclavate, 4 to 5-septate, hyaline, 100-140 x 2.5-3 /x. 

Spots are caused on the mignonette aTid the plants are blighted. 
The hyphae appear through the stomata. 

C. odontoglossi P. & D. occurs on cultivated Odontoglossum ; 

C. unicolor S. & P. on lily. 

C. richardiaecola Atk.^^ 

Spots amphigenous, black, with small white centers, subcircular, 
2-6 mm. broad; conidiophores fasciculate, light-brown with a 
reddish tinge, becoming reddish-brown, erect or apically flexuose, 
denticulate, 30-80 x 5 /x; conidia hyaline, obclavate, 4 to 10 
or more septate, 50-100 x 3-4 /t. 

On calla lily. 

C. microsora Sacc.^^ 

Spots amphigenous, minute, brown, gregarious; conidiophores 
subfasciculate from a tubercular stroma, short, continuous, sub- 
olivaceous, 20-30 X 3 ju; conidia filiform, 3 to 5-septate, con- 
stricted at the septa, olivaceous, 35—15 x 3.5 fj.. 

It causes spotting and defoliation of Tilia. 

C. cercidicola E. 

Spots amphigenous, dull grey above, rusty-brown beneath, 
with a blackish-brown raised border; conidiophores amphigenous, 



632 THE FUNGI WHICH CAUSE PLANT DISEASE 

fasciculate, brown, 90-114 x 3.5-4 fi, subgeniculate above; conidia 
oblong, clavate, faintly 3-septate, 30-40 x 5-7 /x. 

It seriously injures the Japanese red-bud and occurs also on the 
American species.^^^ 

C. acerina Hartig is on maple seedlings. 

C. sequoiae E. & E. 

Large compact olivaceous tufts are formed on languid leaves; 
conidiophores ferruginous, brown, abruptly bent, subnodose, 
toothed, sparingly septate, 50-70 x 4-5 fi; conidia oblong, becom- 
ing clavate, 40-70 xQ n, concolorous with the hyphse, 3 to 5-septate, 
constricted at the septa. 

It is said to seriously interfere with the growth of Sequoia in 
the eastern states. 

C. halstedii E. & E. 

Spots hypophyllous, indefinite, brownish to olivaceous, 2-4 mm. 
across; conidiophores few-septate, 100-150 x 5-7 /x, undulate or 
crisped; conidia obclavate, 65-80 x 5-7 n, 3-septate, somewhat 
constricted. 

It produces blotches on pecan leaves and causes partial de- 
foliation. ^^^ 

Stilbaceae (p. 565) 

Sterile hyphae creeping, scanty; fertile hyphse collected into a 
stalk-like or stroma-like fascicle, bearing conidia at the top, more 
rarely along the sides, pale, bright-colored or dark. 

Key to Sections of Stilbaceae 

Hyphse and conidia hyaline or light 

colored I. Hyalostilbeae. 

Conidia globose, elliptic or oblong 

1-celled 1. Amerosporae, p. 633. 

2-celled 2. Didymosporae. 

3 to several-celled 3. Phragmosporae. 

Conidia filiform, coiled 4. Helicosporae. 

Hyphse or conidia dark II. Phaeostilbeae. 

Conidia globose, elliptic, or oblong, 
With cross walls only 

1-celled 5. Amerosporae, p. 635. 



THE FUNGI WHICH CAUSE PLANT DISEASE 633 

2-celIed 6. Didymosporae. 

3 or more-celled 7. Phragmosporae, G37. 

Muriform 8. Dictyosporae. 

Conidia of a stellately arranged group of 

cells 9. Staurosporae. 

Hyalostibeae-Amerosporae (p. 632) 

Bright or light-colored, conidia globose, elliptic or oblong, 
continuous. 

Key to Genera of HyalostibeaB-Amerosporae 

Conidial part distinctly capitate or at least 
terminal 
Conidia not in chains 
Head of conidia not gaping or split- 
ting above 
Head not spiny 

Conidiophores of head normal 
Conidia covered with mucus 
Synnema monocephalous 
Conidiophores dendroid- 
verticillate 
Without distinct sterig- 

mata 1. Dendrostilbella. 

With obpiriform sterig- 

mata 2. Pirobasidium. 

Conidiophores not dendroid- 

verticillate 3. Stilbella, p. 635. 

Synnema polycephalous 
Capitula on extremely 

short branches 4. Polycephalum. 

Capitula on spreading 

subulate branches ... 5. Tilachlidium. 
Capitula on erect 

branches 6. Corallodendron. 

Conidia without mucus 
Synnema monocephalous 
Conidiophores spirally 

twisted 7. Martindalia. 



634 THE FUNGI WHICH CAUSE PLANT DISEASE 

Conicliophores more or less 
straight 
Conidia rhombic or 

biconic 8. Rhombostilbella, p. 635 

Conidia globose to fu- 

soid 9. Ciliciopodium. 

Synnema polycephalous 
Terrestrial, large, 1-2 cm.; 

conidia ovoid 10. Macrostilbum. 

Not terrestrial, small; co- 
nidia elongate-ovate. . 11. Chondromyces. 
Conidiophores conidium-like, sep- 
tate; monocephalous 12. Atractiella. 

Head spiny with radiating spic- 
ules 

Spicules conic, granulate 13. Actiniceps. 

Spicules with many . curved 

branches at middle 14. Heterocephalum. 

Head of conidia persistent below, 

splitting above 15. Pilacre. 

Conidia in chains 
Synnema with conidia above; conidia 
without mucus 

Synnema not pubescent 16. Coremium, p. 635. 

Synnema pubescent 17. Lasioderma. 

Synnema with conidia below; conidia 

with mucus 18. Microspatha. 

Conidial part cylindric or long-clavate 
Conidia more or less equally scat- 
tered 
Sterigmata denticulate, branched ... . 19. Cladosterigma. 

Sterigmata none or simple 20. Isaria, p. 635. 

Conidia in lateral heads or racemes 
Conidia in racemes; synnema lo- 

bate 21. Peribotryum. 

Conidia in heads 
Conidiophores with lateral nodes, 
usually escaping through the 

stomata 22. Helostroma. 

Conidiophores without nodes, usu- 
ally entomophilous 23. Gibellula. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



635 



Stilbella Lindau (p. 633) 

Hyphse forming a coremium which is capitate above; conidio- 
phores borne on the cap; conidia small, often enclosed in slime. 

Over one hundred species chiefly saprophj'^tes. (Commonly 
known as Stilbum but the type of the genus being a hymenomycete 
it was renamed.) 

S. flavida (Cke.) Kohl, causes a serious coffee disease. 

S. theae Bern, is on tea in India. 

S. nanum Mas. causes the thread blight of tea. 

S. populi on poplar =Mycosph8erella populi. See p. 250. 

Rhombostilbella Zimmermann (p. 634) 

Synnemata verticillate-stilbiform; conidia rhomboid to biconic, 
acute, without mucus. Monotypic. 

R. rosae Zimm. is found on Liberian coffee. ^^^ 



Coremium Link (p. 634) 

Coremium cylindric, apically enlarged and 
fertile; conidia very small, catenulate. A 
small genus. In part = Rosellinia and Penicil- 
lium. See p. 230. 

Isaria Persoon (p. 634) 

Stromata erect, clavate or branched, fer- 
tile throughout, hairy; conidia small, globose 
to ellipsoid, hyaline. 

Over one hundred species, chiefly entomog- 
enous. 

I. fuciformis Berk, is reported from Eng- 
land and Australia forming its stromata 
on the inflorescences of Festuca. 

I. graminiperda B. & M. also causes con- 
siderable injury to grasses in Australia. ^^^ 











Fig. 429. — Coremium 
glaucum. After 
Corda. 



Phaeostilbeae-Amerosporae (p. 632) 
Dark conidia continuous, globose to elongate. 



636 THE FUNGI WHICH CAUSE PLANT DISEASE 



Key to Genera of Phaeostilbeae-Amerosporae 

Conidia not in chains 

Synnema setose 1. Saccardaea. 

Synnema naked 

Conidia asperate, on minute basidia. . . 2. Basidiella. 
Conidia smootli 
Synnema carnose, racemose-branclied 3. Stilbothamnium. 
Synnema fibrous or corneous, not 
racemose 

Conidiophore lageniform 4. Ceratocladium. 

Conidiophore lacking, at least not 
lageniform 
Synnema stalked, fibrous 

Conidia dark, globose to ellip- 
tic 5. Sporocybe. 

Conidia hyaline 

Conidia ovoid to oblong. . . 6. Graphium. 
Conidia elongate or falcate. 7. Harpographium. 

Synnema sessile, corneous 8. Glutinium. 

Conidia in chains 

Synnema setose 9. Trichurus. 

Synnema not setose 

Stalk branched above 10. Stemmaria. 

Stalk simple or nearly so 
Capitule loose 

Base of synnema subequal; usually 

on stems 11. Stysanus, p. 636. 

Base of synnema perithecioid; 

usually on leaves 12. Graphiothecium. 

Capitule compact 
Conidia globose 

Conidia echinulate 13. Harpocephalum. 

Conidia smooth 

Conidia pleurogenous 14. Heydenia. 

Conidia acrogenous 15. Briosia. 

Conidia ovoid to oblong 16. Antromycopsis. 

Stysanus Corda 
Stromata erect, cylindro-clavate, dark, rigid ; conidia in an oblong 



THE FUNGI WHICH CAUSE PLANT DISEASE (,37 

or subglobose panicle, ovoid, lemon-shaped or fusoid, subhya- 
line. 

Some twenty-five species. See Fig. 430. 

S. veronicae Pers. occurs on cultivated Veronicas in Italy; 

S. ulmariae M'W. on Spirea in Ireland. 

S. stemonitis Cda. causes a brown rot of potatoes in storage. 

Phaeostilbeae-Phragmosporae (p. G33) 

Conidia 3 to several-celled, oblong to cylindric, dark or hya- 
line. 

Key to Genera of Phaeostilbeae-Phragmosporae 

Conidia capitate 
Synnema simple 

Synnema black; conidia densely capi- 
tate 1. Arthrobotryum. 

Synnema fuscous or pale; conidia 

loosely capitate 2. Isariopsis, p. 637. 

Synnema dendroid-branched 3. Xylocladium. 

Conidia not capitate 

Conidia catenulate 4. Dendrographium. 

Conidia not catenulate 
Stalk fibrous 

Synnema simple or branched ; conidia 

acro-pleurogenous 5. Podosporium. 

Synnema branched; conidia acro- 

genous 6. Negeriella. 

Stalk parenchyma-like 

Conidia pleurogenous, on a disk. ... 7. Riccoa. 
Conidia acrogenous 8. Podosporiella. 

Isariopsis Fries 

Slender, dark or subhyaline, cylindric hyphse laxly aggregated; 
conidia in a lax panicle or head, cylindric or clavate. See Fig. 431. 

I. griseola Sacc. 

Spots hypophyllous, ochraceous; coremium stipitate, dense. 
200 X 30-40 n, composed of filiform hyphse; conidia borne on 
the reflexed ends of the hyphse, cylindric-fusoid, curved, 50-60 
X 7-8 n, grey, 1 to 3-septate, constricted. 

It causes disease of beans. 



638 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Tuberculariaceae (p. 565) 
Hyphse compacted into a globose, discoid, or verruciform body, 




Fig. 430. — Stysanus. 
After Saccardo. 



Fig. 431. — Isariopsis. 
After Saccardo. 



the sporodochium; sporodochia typically sessile, waxy or subge- 
latinous, white, bright-colored or dark to black. 

In part =Nectria, Claviceps and Hymenoscypha, etc. See 
pp. 146, 201, 211. 

Key to Sections of Tuberculariaceae 



Hyphse and conidia hyaline or bright-colored 
Conidia glol^ose to fusoid or falcate 

Conidia continuous 

Conidia 1-septate 

Conidia 2 to many-septate 

Conidia muriform ." 

Conidia spirally coiled 

Conidia forked or cruciate 

Hyphse olive to brown or black; conidia 

concolorous, rarely hyaline 

Conidia globose to elongate 

Conidia continuous 

Conidia 1-septate 



I. Mucedineae. 

1. Amerosporeae, p. 639. 

2. Didymosporae. 

3. Phragmosporae, p. 645. 

4. Dictyosporae. 

5. Helicosporae. 

6. Staurosporae. 

II. Dematieae. 

7. Amerosporae, p. 654. 

8. Didymosporae. 



THE FUNGI WHICH CAUSE PLANT DISEASE 639 

Conidia 2 to many-septate 9. Phragmosporae, p. 657. 

Conidia muriform 10. Dictyosporae, p. 658. 

Conidia filiform, hyaline 11. Scolecosporae. 

Conidia spirally twisted 12. Helicosporae. 

Conidia angulo^e-stellate 13. Staurosporae. 



Tuberculariaceae-Mucedineae-Amerosporae (p. 638) 

Conidia hyaline, or bright-colored, continuous, globose to fusoid; 
hj'phce hyaline. 



Key to Genera of Tuberculariaceae-Mucedineae-AmerosporeaB 

Sporodochia smooth or nearly so 
Conidiophores normal 
Conidia muticate 
Conidia not covered with mucus 
Conidia not acrogenous-capitate 
Sporodochium girt by a heterogenous 

cup 1. Patellina. 

Sporodochium without a heterogenous 
cup 
Conidia not catenulate or scarcely so 
Conidia escaping from interior of 
hyphai 

Conidiophores branched 2. Endoconidium, p. 641. 

Conidiophores simple 3. Trichotheca. 

Conidia arising on outside of hyphjE 
Conidiophores lacking 
Conidia large, pellucid 

Conidia globose 4. Sphaerosporium. 

Conidia oval 5. Diaphanium. 

Conidia small, not pellucid 6. Pactilia. 

Conidiophores present 
Conidia pleurogenous or acro- 
pleurogenous 

Conidia globose 7. Beniowskia. 

Conidia ovoid to oblong 8. Tubercularia, p. 642. 

Conidia fusoid to cylindric 9. Fusicolla. 

Conidia acrogenous 



640 THE FUNGI WHICH CAUSE PLANT DISEASE 

Conidiophores vermcose 10. Dacrymycella. 

Conidiophores not verrucose 

Uredinicolous 11. Tuberculina. 

Not uredinicolous 
Sporodochia globose 
Conidia globose ; conidio- 
phores short 12. .ffigerita. 

Conidia ovoid ; conidiophores 

branched 13. Granularia. 

Sporodochia pulvinate 

Conidia acicular 14. Kmetia. 

Conidia terete-oblong 15. Bactridiopsis. 

Sporodochia disk-shaped 16. Hymenula. 

Sporodochia cupulate 17. Hyphostereum. 

Sporodochia verruciform or 
effuse 
Conidiophores simple 
Conidiophores radiate, 

united at base 
Conidiophores not arising 

from a cellular mass. . 18. Clinoconidium. 
Conidiophores arising from 

a cellular mass 19. Ustilaginoidea, p. 643. 

Conidiophores not united or 

radiate 20. Sphacelia, p. 643. 

Conidiophores dendroid 

branched 21. Dendrodochium, p. 643. 

Conidia in chains 

Conidia covered with mucus. ... 22. CoUodochium. 
Conidia without mucus 
Conidia globose 

Conidia hyaline 23. SphaerocoUa. 

Conidia blue 24. Sporoderma. 

Conidia elliptic to oblong 
Sporodochium disk-shaped, 

orange-red 25. Necator, p. 643. 

Sporodochium subglobose, 

whitish 26. Patouillardia. 

Conidia cylindric 
Sporodochium dilated above, 

stalked 27. Bizzozeriella. 



THE FUNGI WHICH CAUSE PLANT DISEASE 641 

Sporodochia globose to verruci- 
form 
Sporodochia gelatinous, sessile 28. Cylindrocolla. 
Sporodochia not gelatinous, 

short-stalked 29. Sphaeridium. 

Conidia acrogenous-capitate; sporo- 
dochia turbinate 30. Cephalodochium. 

Conidia covered with mucus 

Sporodochium globose, hardened 31. Thecospora. 

Sporodochia verruciform or subeffuse. . 32. Illosporium, p. 643. 

Sporodochia discoid 33. Epidochiopsis. 

Conidia ciliate 

Conidia 1-ciliate at base only 34. Stigmatella. 

Conidia 1-ciliate at each end 35. Thozetia. 

Conidia 7 to 8-ciliate at each end 36. Chaetospertaum. 

Conidiophores with internal conidia- 

bearing areoles 37. Scoriomyces. 

Sporodochia setulose, ciliate or uniformly 
woolly 
Sporodochia woolly or setulose 
Sporodochia setulose; conidia catenu- 

late 38. Periola. 

Sporodochia woolly or velvety; conidia 
capitate 

Conidia globose 39. Dacryodochium. 

Conidia oblong 40. Lachnodochiuin. 

Sporodochia ciliate at the margin 

Sporophores none; conidia coacervate . . . . 41. Volutellaria. 
Sporophores distinct 

Conidia in chains 42. Volutina. 

Conidia not in chains 
Conidiophores 6-ciliate above, united 

below 43. Guelichia. 

Conidiophores not ciliate or united. ... 44. Volutella, p. 644. 

Endoconidium Prillieux & Delacroix (p. 639) 

Sporodochia pulvinate, white; conidiophores hyaline, racemose; 
conidia hyaline, rounded, formed within the conidiophore and 
escaping apically. 

A small genus, chiefly saprophytes. 



642 



THE FUxNGI WHICH CAUSE PLANT DISEASE 



E. temulentum P. & D. = Hymenoscypha temulenta. See 
p. 146. 

Tubercularia Tode (p. 639) 

Sporodochium tubercular or wart-like, sessile or subsessile, 
smooth, rarely with bristles, usually reddish; conidiophores very 




Fig. 432.— Hyphas 
of Tubercularia, 
bearing conidia. 
After Durand. 




Fig. 433. — T. fici, sporodochium, showing setse 
and conidial formation. After Edgerton. 



In 



slender, usually branched; conidia apical, ovate to elongate 
part=Nectria. See p. 201. 

Over one hundred species, chiefly saprophytes. 

T. vulgaris Tode=Nectria cinnabarina. See p. 202. 

T. fici Edg.^'^' 361 

Sporodochia scattered or gregarious, superficial or subcuticular, 
light pink, variable in size up to 3-4 x 1-1.5 mm., smooth, irregular 
in outline; conidiophores crowded, hyaline, 20-27 x 1-2 n; 
conidia small, clear, elliptic to oval, regular in size, 5-7 x 2.5-5 /x; 



THE FUNGI WHICH CAUSE PLANT DISEASE 643 

setsB scattered or abundant, variously placed, straight or curved, 
hyaline or subhyaline, septate, papillose, 60-90 x 4-6 ai. 
It is the cause of a fig canker. 

Tuberculina Saccardo 

Several species occur in sori of the Uredinales. 

Ustilaginoidea Brefeld, a small genus of Ascomycetes, one species 
of which, U. virens, on rice is known only in the conidial stage. 
See p. 214. 

Sphacelia L^vielle (p. 640) 

Sporodochia planose, effuse, stromate or sclerotioid; conidio- 
phores short, simple, filiform; conidia apical, ovate, 

A small genus, chiefly conidia of Claviceps and related genera. 
S. segetum Lev. = Claviceps purpurea. See p. 212. 
S. typhina (Pers.) Sacc. =Epichloe typhina. See p. 210. 

Dendrodochium Bonardin (p. 640) 

Sporodochium pulvinate or verruciform, white or light-colored; 
conidiophores verticillate, branched; conidia acrogenous, ovoid to 
oblong. 

A genus of about forty species. 

D. lycopersici March is found on tomatoes in Belgium.^^^ 

Necator Massee (p. 640) 

Sporodochium erumpent, small, slightly convex, becoming 
orange-red; conidia oblong or elliptic, catenulate, contents orange. 
Monotypic. 

N. decretus Mas. is a dangerous parasite of coffee, tea, etc.^^^' ^^^ 

Illosporium Martius (p. 641) 

Sporodochia wart-like, pulvinate or subeffuse, white or light- 
colored, subgelatinous or waxy; conidiophores variable; conidia 
globose, sigmoid, variable, embedded in mucous. There are some 
forty species. 

I. malifoliorum Shel. 

Spots suborbicular or coalescing and becoming irregular, brown 



644 



THE FUNGI WHICH CAUSE PLANT DISEASE 




Fig. 434.— lUospo- 
rium maculicola 
After Saccardo. 



or mottled with gray and with a small gray spot near the center, 
5-15 mm. in diameter; sporodochia hypophyllous, minute, gelat- 
inous, yellow-amber, becoming black, spherical, becoming discoid 
or irregular, 150-160 /x in diameter; conidio- 
phores branched; conidia oblong, 1-3.5 x 4 /x. 

It is said by Sheldon ^^^ to be one of the most 
common and destructive causes of leaf spots of 
the apple often resulting in nearly complete de- 
foliation. In the centers of the leaf spots other 
spots bearing other species of fungi are often 
found, leading to the thought that perhaps the 
Illosporium in such cases results from secondary infection in the 
wounds made by the earlier fungus. The sporodochia are hypo- 
phyllous, often hidden by the normal pubescence of the leaf. 

Volutella Tode (p. 641) 

Sporodochia discoid, regular, margin ciliate, sessile or stipitate; 
conidiophores usually simple; conidia ovoid to oblong. 

Some seventy species. 

V. leucotricha Atk. 

Sporodochia convex-discoid, white to pale flesh-color; setse few, 
filiform, few-septate, subhyaline ; conidiophores densely fasciculate, 
filiform; conidia oblong. 

On cuttings in greenhouses. 

V. fructi S. & H. 

Spots on the fruit, circular; sporodochia, numerous in concentric 
circles, subcu ti c ul ar, 
erumpent, elevated 200- 
250 n, 150-400 /x in 
diameter; mycelium 
black; seta? distributed 
throughout the sporodo- 
chium, black, to 3- 
septate, acute, smooth, 
100-400 X 5-8 fJL] co- 
nidiophores elongate, hyaline, simple, 25-35 x S /i; conidia 
smooth, oblong-fusoid to falcate-fusoid, hyaline or sub-olivaceous, 
17-23 X 2.5-3.5 fi. 




Fig. 435. — V. fructi. Sporodochia in section. 
After Stevens and Hall. 



THE FUNGI WHICH CAUSE PLANT DISEASE 645 

It is the cause of a dry rot of apples.^^' ^^^ 
V. dianthi (Hal.) Atk.-^ 
It is the cause of anthracnose of carnation. 
The acervuH are conspicuous with black seta?. 
V. concentrica Hals, is reported by Halsted as the cause of leaf 
spots of Bletia.^^ 

Tuberculariaceae-Mucedineae-Phragmosporae (p. 638) 

Hypha3 hyaline; conidia 2 to several-septate, hyaline or bright- 
colored, fusoid to falcate, rarely short and simple in some species 
of Fusarium. 

Key to Genera of Tuberculariaceae-Mucedineae-Phragmosporae 

Conidia somewhat catenulate, cylindric. .. . 1. Discocolla. 
Conidia rarely catenulate 

Conidia cruciately 4-celled; sporodochium 

gelatinous 2. Sarcinodochium. 

Conidia not cruciate 

Conidiophores short, simple 

Conidia very large, terete-oblong. . . 3. Bactridium. 

Conidia doliform 4. Pithomyces. 

Conidiophores more or less branched 
Conidiophores dichotomous; conidia 

key-like 5. Heliscus. 

Conidiophores usually verticillately 
branched, conidia usually fal- 
cate, sometimes oblong 

Sporodochium gelatinous 6. Pionnotes, p. 645. 

Sporodochium waxy or byssoid ... 7. Fusarium, p. 646. 

Pionnotes Fries 

Sporodochium gelatinous, then firm, orange, pulvinate or lobed; 
conidiophores fasciculate, simple or branched; conidia rather large, 
fusoid to cylindric, curved. 

Only twelve or fifteen species, chiefly saprophytes. 

P. betae Mas. occurs on mangels and beets and according to 
Massee is probably identical with P. rhizophila which attacks 
stored Dahlia roots and potatoes. 



646 THE FUNGI WHICH CAUSE PLANT DISEASE 

Fusarium Link (p. 645) 

Sporodochiiim pulvinate, or subeff used ; conidiophores branched ; 
conidia terminal, solitary, fusiform or falcate, more or less curved, 
pluriseptate. 

In part=Nectria, Neocosmospora, Gibberella. See pp. 201, 
205, 206. 

This is a large genus, (some four hundred species have been de- 
scribed) though future study will undoubtedly relegate many 
names to synonymy. 

Many of the species are destructive parasites, invading the ducts 
of plants and by stoppage of the water-supply causing the class of 
diseases known as "wilts." Others induce rot, spotting, cankers, 
etc. Taken as a whole the genus is one of the most injurious with 
which plant pathology has to do. 

It seems probable that some of the forms that live normally as 
saprophytes in soil may encroach upon living roots of susceptible 
plants when these are available. 

In nature the spores typical of this form-genus are borne in 
sporodochia, coremia or acervuli and are crescent-shaped or fusoid. 
The same mycelium that produces these structures often, indeed 
usually, produces also similar and smaller conidia scattered 
on single hyphce (=Cephalosporium). These two forms are called 
macroconidia and microconidia respectively. Tlie microconidia 
are regarded by Appel & Wollenweber ^^^ as depauperate mac- 
roconidia. Frequently chlamydospores form in the mycelium; 
either terminal or intercalary. Sclerotia are also not uncom- 
mon. 

Undoubted species of Fusarium have been shown to belong to 
several different Hypocrealous ascomycetes, while still more have 
as yet revealed no ascomycete connection. 

Biologic specialization has been found, in that forms morpho- 
logically indistinguishable are frequently incapable of cross in- 
oculation onto other than their usual hosts. 

Fusarium grows well in culture and the species often show 
marked differences in growth on various media, particularly in 
the colors that are developed. 

As with the anthracnoses much study is here needed to throw 



THE FUNGI WHICH CAUSE PLANT DISEASE 



647 



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648 THE FUNGI WHICH CAUSE PLANT DISEASE 

light on the inter-relation of the various species and their hosts. 
Apple & Wollenweber ^'^^ have made an extensive study of several 
species to lay the ground for a monograph. They conclude that 
in delimiting species important characters are the forms of the 
conidia, especially their bases, apices, and degree of curvature and 
septation (see Fig. 436); the color of the mycelium and spores; 
the presence or absence of chlamydospores. They cast aside as 
valueless many earlier descriptions substituting new diagnoses 
and new names. According to their conception, the following 
names should stand. 

F. solani (Mart.) Sacc. =Fusisporium solani Mart. =Fusarium 
commutatum Sacc. 

F. martii A. & W. =Fusisporium solani Mart. 

F. coeruleum Lib. =Fusarium solani. 

F. discolor A. & W. =Fusarium solani. 

F. rubiginosum A. & W. =Fusarium solani. 

F. discolor var. sulphureum (Schl.) A. & W. =Fusarium sul- 
phureum Schlecht. 

F. subulatum A. & W. 

F. metachroum A. & W. 

F. orthoceras A. & W. =F. oxysporum Sm. & Sw. not Schl. 

F. theobromae A. & Struk. 

F. wilkommii Lin. =F. bacilligerum B. & Br. 

F. falcatum A. & W. =F. vasinfectum pisi Schk. 

F. gibbosum A. & W. 

It will be noted that several of the species mentioned below 
are here involved. 

F. platani Mont. =Calonectria pyrochroa. See p. 205. 
F. rubi Wint. 

Mycelium white, becoming pink, especially 

abundant on the flowers; conidia elongate, 1 

to 8-septate, variable in size and form, 

„ ,. ^ straight or curved, 14-30 x 3-3.5 ju, not con- 

FiG. 437. — Section of . ' 

ovary showing my- stncted. 

pei^aml ovuie.^^After Cook ^^^' ^^^ found this fungus in diseased 
^°°^' buds of dewberries and by inoculation dem- 

onstrated that it is responsible for witches-broom, double- 
blossom, and similar abnormal growths of this plant. 




THE FUNGI WHICH CAUSE PLANT DISEASE 649 

F. gemmiperda Aderh. is described by Aderhold ^™ as fatal to 
flower buds of cherry before they open, a conclusion supported by 
inoculation experiments. The disease in general appearance re- 
sembles sclerotiniose. 

F. rhizogenum P. & C. 

Sporodochia superficial, 1 to 2 mm. wide, dense, convex, white 
or whitish, hyphae densely interwoven, septate, subramose; conidia 
oblong, roundish, 1-septate, 70 x 4 ;u. 

It was originally described as a parasite on apple roots in Ne- 
braska ^^^ and is mentioned by Aderhold ^° as the cause of death of 
roots of apple and cherry trees in Europe. The mycelium grows 
within the roots and gummosis of the wood occurs. A Cephalo- 
sporium form is known, also chlamydospores. 

F. putrefaciens Osterw.^^^'^^'' is said by Osterwalder ^''^ to cause 
decay of pomaceous fruits. 

F. cubense E. F. Sm. was isolated from bananas affected with 
blight. Inoculation showed the fungus capable of growing through 
the bundles for long distances.^''^ 

F. limonis Bri.i^O' ^'^' '^'^ 

Sporodochia gregarious, confluent, white; hyphse spreading, 
branched, septate; conidiophores erect, with alternate or opposite 
branches; conidia variable, acrogenous, continuous to 3-septate, 
oblong to fusiform, curved, pointed, slightly constricted, 26-27 x 
2.4-2.8 II. 

This fungus is held to be contril^utory to, if not responsible for, 
the Mal-di-gomma or foot-rot of citrous 
fruits which is known practically wherever 
these fruits are cultivated. 

F. culmorum (W. Sm.) Sacc.^^^' ^^^ 

Reddish-yellow, gelatinous, effuse; hyphae 
few-septate, tortuous; fertile, short, con- 
tinuous; conidia fusoid-falcate, 3 to 5-sep- 

tate, 28-32 X 6-8 /x on wheat. Fig. 438.— F. culmorum. 

The fungus affects chaff and seed, first After Chester, 

appearing as a whitening of the upper halves of the glumes fol- 
lowed later by a pink color. The glumes become cemented to- 
gether and the whole head may be involved. The grains are of 
light weight and are often covered with the fungus. Chester 




650 



THE FUNGI WHICH CAUSE PLANT DISEASE 



showed that the mycelium penetrates the seed and may even 
consume it entirely. 

F. sp. occurs on raspberry.^^* 

F. moniliforme Shel. 

Sporodochium subeffuse, salmon-pink; conidiophores simple 
or with opposite branches; microconidia continuous, oblong-ovoid, 





Fig. 439. — Fu^^arium 
on corn. After 
Burrill and Bar- 
rett. 



Fig. 440. — F. vasinfectum. A. Macro- 
conidia. B. Portion of a hypha. 
C. A germinating macroeonidium. 
After Reed. 



380-383 



moniliform, 6-10 ju long; macroconidia falcate, acute, usually 
3-septate, 25-40 /x long. 
It causes molding of corn.^"^ 

Several other undetermined species have been isolated from 
corn on which they occur as the cause of dry rot of the grain. ^"^ 

A fusarium on banana is by Essed referred to Ustilaginoidella. 
See p. 214. 
F. vasinfectum Atk.' 
Hyphse at maturity yellowish, 2-4 ju in diameter; conidia borne 

singly; microconidia oval, con- 
tinuous; macroconidia falcate, 2 to 
3-septate, 1-2 x 2-4 /i. 

Atkinson ^^^ first described this 
on cotton and okra in which 
plants it was found plugging the 
ducts with its mycelium. The 
m3''celium here was 2-4 fj. in diameter and microconidia were 
seen within the ducts. Pure cultures were obtained and inocula- 
tions with these on plants already injured by Pythium resulted in 




Fig. 441. — F. v^asinfectuni. D. Mi- 
croconidia. E. Chlamydo.spores 
After Reed. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



651 




infection. The ascigerous stage was said by Smith ^^° to be a 
Neocosmospora and the many wilts caused by Fusarium have by 
various authors who follow 
Smith been reported as 
Neocosmospora though 
without real evidence that 
they are such. See 
page 205. 

Recent studies of Hig- 
gins ^^^ and Butler ^^^ in- 
dicate that the Fusarium 
of the Neocosmospora is 
a saprophyte and that the 
Fusariums parasitic in the 
wilt diseases are as yet 
unknown in ascigerous 
form. 

The Fusarium parasitic 
on cotton is believed 
be identical with that on 
okra but distinct biologically if not morphologically from that 
of watermelon. 

F. vasinfectum var. tracheiphila E. F. Sm.^^^ 

This form on cowpea, which appears to be morphologically 
identical with F. vasinfectum is not capable of infecting cot- 
ton. 

F. niveum E. F. Sm.^^*'" ^^-"^^* is the cause of the watermelon 
wilt. Morphologically it is Hke F. vasinfectum. 

A fungus regarded by Reed ^^' ^^^ as identical with this was also 
described as causing wilt of ginseng. 

F. vasinfectum var. pisi v. Hall has been described as a variety 
affecting the pea.^^^' ^^^ 

F. udum Butler on pigeon pea in India is closely related to 
this last fungus. 

F. aurantiacum (Lk.) Sacc. is recorded for cucurbs occurring 
on stems, leaves and fruits. 

F. oxysporum Schl.^^^' ^^^ 

Sporodochia convex, subverrucose, rose, erumpent,. confluent; 



to Fig. 442. — F. vasinfectum, showing thrombosis 
of veins. After Atkinson. 



652 THE FUNGI WHICH CAUSE PLANT DISEASE 

conidia on short conidiophores; microconidia continuous, elliptic; 
macroconidia falcate-fusoid, 3 to 4-septate, 40-60 x 7-8 n. 

Smith and Swingle ^^^ mention 1 1 described species of Fusarium 
recorded by Saccardo for the Irish potato, viz. ; 

Fusarium oxysporum Schl., F. (Fusisporium) solani (Mart.) 
Sacc, F. (Fusisporium) solani-tuberosa Mart., F. didymum 
Harting, F, solani Schl., F. (Fusisporium) roseolum (B. &. B.) 
Sacc, F. violaceum Fcl., F. caruleum (Lib.) Sacc, F. diplosporum 
C. & E,, F. commutatum Sacc, F. pestis Sorauer, F. aeruginosum 
Delacroix, F. acuminatum E. & E., F. affine Fautr. & Lamb, all 
of which they tentatively regard as synonyms, attributing such 
differences as have been noted in descriptions to variations in the 
environment under which the fungus was growing when described. 
The potato disease caused is common over a considerable portion 
of the United States and is variously known as "bundle blacken- 
ing," "stem rot," "dry end rot," and "dry rot." 

The fungus grows readily on many culture media, showing large 
variation with the environment. It is aerobic and tolerates large 
amounts of malic, citric and tartaric acids. 

F. acuminatum E. & E. Sporodochia gregarious, minute, whitish 
or flesh-colored; conidia falcate, attenate, 3 to 5 or 6-septate, 
not constricted. 

Described by Stewart ^^^ as causing a girdling of potato stems in 
New York. 

F. roseum-lupini-alba Sacc 

Sporodochia pulvinate, minute, confluent, cinnabarine; co- 
nidiophores variable, long, slender, branched, branches nodulose, 
fusoid; conidia fusoid falcate, 45-55 x 4 /z, 4 to 6-septate. It 
causes spots on leaves and pods of lupines and attacks the seeds, 
inducing rot. 

F. cucurbitariae Sacc. is on cucumbers in Queensland. 

F. solani (Mart.) Sacc. 

Sporodochia globose, irregular, white; conidiophores branched; 
conidia fusoid-falcate, 3 to 5-septate, 40-60 x 7-8 fx, subhyaline. 

Clinton, ^^^ also Wehmer ^^^ and others, have shown this to be 
the cause of "dry end rot " of stored potatoes. It may be iden- 
tical with F. oxysporum. 

F. pestis Sor. is given by Sorauer as the cause of "black-leg" 



THE FUNGI WHICH CAUSE PLANT DISEASE 



653 




Fig. 443. 



After Bolley. 



(see p. 46) of potatoes; it is perhaps identical with F. oxy- 
sporum. 

F. erubescens A. & v. Ov. produces small black sunken spots 
on green and ripe toma- 
toes in German}^ '^^ re- 
sulting finally in mummi- 
fication. Parasitism by 
means of enzymes was 
demonstrated. 

F. lycopersici Sacc.'"'^"^°'' 

Sporodochia as in F. oxy- 
sporum; conidia falcate, 
acute, 25-30 x 3.5-4 /z, 
hyaline to yellowish. 

It is the cause of a to- 
mato wilt or "sleeping 
disease" resulting from in- 
vasion of the ducts. Conidia of two kinds are produced, Fusa- 
rium and Diplocladium. Infection is subterranean. 

A nearly related disease differing chiefly in the fact that the 
fungus does not reach far above ground has been described by 
Smith.'"'- The fungus in both cases is perhaps identical with 

F. oxysporum. 
F. lini Boll. 403 

Sporodochia erum- 
pent, compact, cream 
to flesh-colored; co- 
nidiophores short, 
much-branched ; co- 
nidia 3-septate, fusi- 
form, slightly curved 
to falcate, 27-38 x 
3-3.5 ^. 

A serious widespread flax wilt is caused. The mycelium develops 
luxuriantly from bits of diseased stem laid in sterile Petri dishes 
and grows well in culture media. Normally a soil saprophyte, it 
invades the roots, grows through the veins, plugs the ducts and 
causes death. The sporodochia are found abundantly on the bases 




Fig. 444. — F. lini, sketch, showing the mode of attack 
upon a young root tip of a seedling flax plant. 
After Bolley. 



654 THE FUNGI WHICH CAUSE PLANT DISEASE 

of diseased plants. The spores abound on all diseased parts, 
particularly on the seeds. Infection experiments have demon- 
strated its pathogenicity. 

F. tabacivorum Del. is said to cause a rot of tobacco in 
France. 

F. brassicae Thiim. is of economic importance on cabbage. '^°^ 

Inoculations of an undetermined species of Fusarium in pure 
culture into soil also resulted in infection of 83% of the cabbage 
plants grown therein. 

F. decemcellulare Brick and F. theobromae Lutz. occur on 
cacao. 

F. ricini (Ber.) Bizz. is injurious to the castor oil plant. 

F. incarnatum (Desm.) Sacc. is reported as the probable 
cause of an aster wilt or blight in Europe. ''"^ An undetermined 
species is also reported on China aster by Galloway '^°^' **°^ and 
others. 

A species of Fusarium on carnation leaves following in rust 
sori was reported by Stewart '"'^ and a wilt disease or stem rot of 
carnation was studied by Sturgis.^°^ He found the Fusarium in 
the affected plants, it was isolated and inoculated into the soil 
around the roots of carnations producing disease in several in- 
stances. 

F. pelargonii Crou. is described from geraniums. ^^° 

F. dianthi P. & D.^^^ on Dianthus cuttings, is a wound parasite, 
following insect injury. 

F. violae Wolf. 

Infected areas dark, sunken; sporodochia within the host; 
conidia fusiform-falcate, 28-38 x 4-6 fx, 3 to 5 times septate; 
hyphse hyaline, 4-7 /x in diameter, irregularly branched. It causes 
a disease of roots and stems of pansy. 

F. pini is believed to be the species responsible for a disease of 
pine seedhngs.*^^ 

F. blasticola Rost. causes death of conifer seedhngs in Europe. 

Tuberculariaceae-Dematiae-Amerosporae (p. 638) 

Hyphse olive to brown or black; conidia continuous, rarely 
hyaline globose to elongate, sometimes unequal. 



THE FUNGI WHICH CAUSE PLANT DISEASE 655 



Key to Genera of Tuberculariaceae-Dematiae-AmerosporaB 

Conidia not in chains 
Sporodochia not setose 
Conidiophores lacking 

Lichenicolous 1. Spilomium. 

Not lichenicolous 
Sporodochia gelatinous; conidia 

globose, vesiculose 2. Myriophysa. 

Sporodochia not gelatinous 

Sporodochia hemispheric, with a 

stratum of conidia 3. Spermodermia. 

Sporodochia disk-like, applan- 

ate 4. Sclerodiscus. 

Conidiophores present 

Sporodochia thick, tremelloid 5. Epidochium, p. 656. 

Sporodochia not tremelloid 

Conidiophores with a slender 
apical appendage; conidia glo- 
bose 6. Bonplandiella. 

Conidiophores not appendaged 
Conidia globose 
Sporodochia cellular, uniform 7. Epicoccum, p. 656. 
Sporodochia of three hyphal 

layers 8. Triplicaria. 

Conidia ovoid to bacillar 

Conidiophores bacillar; sporo- 
dochia subdiscoid 9. Hymenopsis. 

Conidiophores branched 
No brown radiate hypha? at 

base 10. Strumella, p. 656. 

Brown radiate hyphse at 

base 11. Astrodochilum. 

Sporodochia ciliate or with exserted hj'^phse 
Sporodochia with loose exserted co- 
nidiophores, verruciform 12. Trichostroma. 

Sporodochia margins with hairs or 
setae 

Setae dark. 13. Chaetostroma, p. 656. 

Setae or hairs white 14. Myrothecium. 



656 THE FUNGI WHICH CAUSE PLANT DISEASE 

Conidia in chains 

Conidiophores lacking 15. Exosporina, p. 656. 

Conidiophores present 

Sporodochia globose 16. Sphaeromyces. 

Sporodochia stellate 17. Actinomma. 

Epidochium Fries (p. 655) 

Sporodochiiim thick, tremelloid, subglobose or wart-form, black 
or pallid, erumpent; sporophores filiform, equal or apicall}^ swollen; 
conidia ovoid, oblong or pyriform, solitary or catenulate. 

Some fifteen species. 

E. oryzae Miy. is found ^^ on rice. 

Epicoccum Link (p. 655) 

Sporodochia globose or convex, cellular, 
dark; conidiophores very short; conidia glo- 
bose. Some fifty species. 

E. hyolopes Miy. is on rice. 

Strumella Saccardo (p. 655) 

Sporodochia wart-shaped; conidiophores 
„ . . r ^ . branched ; conidia ovate, often somewhat bent. 

1<IG. 445. — Epicoccum. ' , ' 

After Saccardo. Some fifteen species. 

S. sacchari Cke. is found on sugar cane.^^^ 

Chaetostroma Corda (p. 655) 

Sori dark or cushion-form black bordered Avith black hairs; 
spores elliptical, fusiform or rarely almost spherical. 

C. buxi Corda on Box=Nectria rousseliana. See p. 204. 
C. cliviae Oud. causes blotches on Clivia. 

Exosporina Oudemaus 

Sporodochia erumpent; conidia catenulate, homomorphic, 
continuous, greenish. Monotypic. 

E. laricis Oud. is parasitic on larch leaves in Europe. 




THE FUNGI WHICH CAUSE PLANT DISEASE 657 



Tuberculariaciae-Dematieae-Phragmosporae (p. G39) 

Hyphffi dark; conidia usually colored, 2 to several-septate, ob- 
long to cylindric. 



Key to Genera of Tuberculariacese-Dematiae-Phragmosporae. 

Conidia in chains; sporodochium discoid. 1. Trimmatostroma, p. 657. 
Conidia not in chains 

Conidia 1-ciliate at each end.. 2. Ciliofusarium. 

Conidia muticate 

Sporodochium hairy 3. Excipularia. 

Sporodochium smooth 

Conidia laterally proliferate and 

joined in bundles 4. Amallospora. 

Conidia not proliferate and 
united 
Sporodochia convex-pulvinate . . 5. Exosporium, p. 658. 
Sporodochia vertically cylindric 

or clavate 6. Listeromyces. 

Trimmotostroma Corda 

Sporodochia pulvinate, compact, bearing a layer of conidio- 
phores; conidia oblong, often curved, 2 to 8-septate, catenulate 
brown. 

A genus of a half dozen species. 

T. abietina Doh.^i^ 

Mycelium perennial; sporodochia foliicolus or caulicolus, 
diffuse; conidiophores subhyaline, or tinged with olive-brown, 
4.5 X 20-30 ju, septate, sparsely branched, bearing the conidia 
terminally; conidia catenulate, very variable, dark olivaceous- 
brown, slightly roughened, usually oblong, spherical, straight or 
inequilateral, continuous, spherical, 5 fi, or 2 to 5-celled and 5-6 
X 8-16 fi, not constricted, rarely muriform, 5 x 10 ju. 

On white and balsam firs in Canada. The perennial habit of 
the mycelium makes the pest a persistent one and as no conidia 
are produced till the second year after infection its presence is 
the more readil}^ overlooked. 



658 



THE FUNGI WHICH CAUSE PLANT DISEASE 



Exposorium Link (p. 657) 

Sporodochia convex, compact; conidiophores dark, simple, 
densely compacted; conidia single, oblong to cylindric, plurisep- 
tate. 

Some twenty-five species. 

In part=Coleroa and Coryneum. See pp. 227, 236. 

E. juniperinum (E.) Jacz. = Coryneum juniperinum. See p. 236. 

E. laricinum Mas. is found on living larch twigs. . 

E. tiliae Lk. grows on young shoots of Tilia. 

E. palmivorum Sacc."*^^ 




Fig. 446. — E. palmivorum. 3, a sporodochium, 
5, spores. After Trelease. 

Spots amphigenous, minute, suborbicular, 1-3 mm. in diameter, 
brown, scattered; sporodochia superficial, densely gregarious, 
punctiform, black; 30 x 60-80 ix; conidiophores oblong, con- 
tinuous, reddish olive, 5-6 x 14-16 n, conidia borne singly, 
fusoid, straight or curved, apically obtuse or acute, basally obtuse, 
8 to 10-septate, not constricted, olive-brown, ends paler, 8-9 x 
80-90 At. 

On palms, especially species of Phcenix in America. 

E. presii Bub. on species of Phcenix in Europe is very similar 
to the preceding species. 

In the Tuberculariacese-Dematiese-Dictyosporse Thjrrococcum 
sirakofii Bubak forms black tubercles under bark of mulberry 
and kills the twigs.^^^ 



THE FUNGI WHICH CAUSE PLANT DISEASE 659 

Mycelia-Sterilia (p. 479) 

Numerous forms are known moroly as sterile mycelia. They 
may or may not make sclerotia. In several instances these sterile 
forms are so aggressive as to warrant classing them among the 
worst of plant pathogens. Until more is known of them it becomes 
necessary to arrange and name them, for convenience of reference, 
in a purely artificial manner. 

Key to form Genera of Mycelia-Sterilia. 

Tubercle-like 

Tubercles connected with fibrils 1. Rhizoctonia, p. 659. 

Tubercles without fibrils 

Cortex discrete 2. Acinula. 

Cortex not discrete 3. Sclerotium, p. 660. 

Maculiform 

Black stromata in leaves and stems 4. Ectostroma. 

Pseudo stromata in cortex 5. Phellomyces. 

Root-like 
Filaments rigid, broad, terete or depressed, 

dark, wliite within 6. Rhizomorpha. 

Filaments rigid, capilliform, dark, closely 

adhering 7. Capillaria. 

Cla variform; filaments terete, vertical, sim- 
ple or branched 8. Anthina. 

Cobwebby or byssoid 

Cespitose interwoven, primary hyphse 

joined in bundles 9. Ozonium, p. 661. 

Cespitose interwoven, hyphse not fascicu- 
late, black 10. Rhacodium. 

Cobwebby, soft, evanescent, white or pale 11. Hypha. 
Adpressed, creeping, dendritic, white to 
brownish, not forming a continuous 

membrane 12. Himantia. 

Membrane-like; densely interwoven, form- 
ing a continuous suberose or coriaceous 
membrane 13. Xylostroma, p. 663. 

Rhizoctonia De Candolle 
Sclerotia variable in form, horn3^-fleshy; cortex thin, mem- 



660 THE FUNGI WHICH CAUSE PLANT DISEASE 

branous, persistent, inseparable; formed among and connected by 
the mycelial threads. 

There are about a dozen so-called species, some of them very 
important plant pathogens. See pp. 407, 408. 

R. betae Klihn and R. solani Klihn = Corticium vagum solani, 
as does also part of what has been referred to as R. violaceai. 

R. medicaginis D. C. (Tul.); ^^ (see also ^^^^ ^i^-'^O- 

Hyphse subtomentose, on the cambium of the host, forming a 
membrane or fasciculate strands, covering the host in time with a 
violet coating; sclerotia reddish-violet. 

On alfalfa in Europe and America.*^^^ 

Duggar who has studied this form and the form allied to Corti- 
cium (pp. 407, 408) regards the two as distinct though Giissow ^^^ 
who has also studied both pronounces them the same. Duggar says, 
"The fungus appears upon the root as a close weft of violet-colored 
hyphae composed of cells more or less uniform in diameter. Mor- 
phologically it bears no resemblance to the sterile stage of Cor- 
ticium." This form is found on alfalfa, asparagus, beet, and pos- 
sibly other plants. 

Leptosphseria has been reported as its ascigerous stage though 
the evidence of such connection is not conclusive. 

R. crocorum D. C. is a form which kills the corms of saffron. 

R. strobi Scholz is the name given to a form described as seriously 
injuring young pine trees in Austria. ^^^ 

R. subepigea Ber. is destructive on the roots of coffee.^^^ 

A Rhizoctonia of undetermined species has been found on buck- 
wheat in the United States.^"^ 

Sclerotium Tode (p. 659) 

Sclerotia roundish or irregular in form, cartilaginous-fleshy, not 
connected by mycelial threads; cortex thin, membranous, in- 
separable. 

Over 200 species have been described. 

S. rolfsii Sacc.2i' ''^s- 438 

Sclerotia small, brown, about the size of a mustard seed. 

This sterile fungus possesses a very aggressive mycelium which 
under favorable conditions of moisture grows on almost anything 
living or dead, producing a dense white cotton-like mass of threads. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



661 



Soon the sclerotia form as mustard-seed-like bodies. They are 
produced in great abundance on all media l)ut neither these struc- 
tures nor the mj^celium have yet been seen to bear spores of any 
kind. The fungus was first studied by Halsted -^ and later by 
many others. It was described and named by Saccardo from speci- 
mens communicated by Stevens. 

S. cepivorum Berk. 

Minute, spherical, gregarious, black. It is found on various 
species of Allium, causing rot. 




Fia. 447. — S. rolfsii, sclerotia. After Halsted. 

S. rhizoides Auer.^-® 

Subglobose, at first white-villose, then smooth, black, rugose. 

On Calamagrostis and other grasses. It causes considerable 
injury to the hay crop in Europe. 

S. tuliparum Klebahn,^-^ S. tulipae Lib. and S. bulborum Wak. 
are found on tulips, and other l)ulbs. A relation to Sclerotinia is 
usually assumed but has not been dem.onstrated. See p. 136. 

S. oryzae Catt. is found on rice in Japan and Italy. 

Ozonium Link. (p. 659) 

Col:)webby or byssoid, cespitose, hyphae densely interwoven, 
primary hyphoe fasciculate. 
Some twelve species. 



662 



THE FUNGI WHICH CAUSE PLANT DISEASE 



O. omnivorum Sh.*'"' ^-^'^^^ 

Mycelium dirty yellow; sometimes whitish when young, grow- 
ing in the vascular bundles of the host; hyphse forming strands 
and spreading from them, producing a rather dense arachnoid 
layer on the surface of the host and l^earing 1 to 4 branches arising 




l-'iG. 448. — S. rolfsii, sterile mycelium growing on carrot. After Stevens and Hall. 



and growing at right angles from the same point near the ends, 
3 to 5 /x in diameter, tapering toward the ends. 

It causes root rot on almost any kind of plant including among 
its hosts a large variety of trees. The first description was by 
Pammel in a Texas Bulletin; a later one was by Shear. The fungus 
destroys the smaller rootlets, cortex of older roots and invades the 
vascular system and medullary rays, resulting in wilt and death. 
It may he seen as dirty yellowish strands or as a thin weft 
superficially. Sclerotia-like bodies appear on the roots often at 



THE FUNGI WHICH CAUSE PLANT DISEASE 663 

lenticels. Inside of the host tissue the mycelium is not typically 
associated to form strands and its cells are hyaline. 

The fungus was in early studies difficult to isolate but Atkinson 
in 1893 **~^ obtained pure cultures by rinsing the diseased roots in 
distilled water, cutting in small pieces and placing on sterile filter 
paper lying on sterile sand in a moist chamber. In a few days the 
strands grew over the paper onto sterilized slides. Bits of sterilized 
cotton-root were then placed in contact with the advancing hyphse. 
Soon the new culture thus secured could be transferred at will. 
A slight acidity retards bacterial growth and renders isolation of 
the Ozonium less difficult. In culture sclerotia about 3 mm. in 
diameter, whitish and woolly, later brown, appear. 

Xylostroma Tode (p. 659) 

This occurs, forming thick, felt-like layers, in cracks of timber. 
It is regarded as the mycelium of various Hjinenomycetes, es- 
pecially Fomes. 

Fungi of Unknown Affinity 

The following imperfectly known genera do not fit readily into 
the scheme of classification and are all in need of careful study. 

Acrocystis Ellis & Halsted 

Monotypic ; though technically a nomen nudem, the illustrations 
are recognizable. Examination of the original material shows 
Saccardo's reference to the Mucorales to be untenable. 

A. batatae E. & H.^^ 

Hyphse intercellular, branched, producing enlarged cysts at the 
ends of branches, the nature of these unknown; enlarged, intra- 
mycelial swellings contain numerous rounded conidia. 

It is described as the cause of soil rot of sweet potatoes. 

Graphiola Poit 

Mycelium within the host; fruiting body rotund, carbonous 
duplex, the outer layer of interwoven branched hyphse, firm, in- 



664 THE FUNGI WHICH CAUSE PLANT DISEASE 

terior softer, of fertile and sterile fasciculate hyphse; fertile hyphae 
with short branches bearing the spore-mother-cells which divide 
into two globose or angular spores; germination by a filiform 
conidia-bearing mycelium. 

A genus of seven species, chiefly on palms. 

G. phoenicis (Moug.) Poit/^^' "'^ 

Sprodochium 1-1.5 x 500 n; exoperidium horny, black, inner 
peridium membranous, hyaline; spore-mass yellow; spores globose 
or elliptic, 3-6 ju, with a thick, smooth, hyaline wall. 

On the date and other palms throughout the world. 



THE FUNGI WHICH CAUSE PLANT DISEASE 



665 





Fig. 449. — G. phoonicis. II, sporiferous organ. 
Ill, section of the same. After Stone and Smith. 



BIBLIOGRAPHY OF FUNGI IMPERFECTI* 

1 Stevens, F. L. and Hall, J. G., Bot. Gaz. 4S: 1, 1909. 

^Leininger, H., C. Bak. 29: 4, 1911. 

' Cobb, N. A., D. Agr. New So. Wales, Miss. Pub. 666: 21. 

* Hedgcock, G., Myc. 10: 2, 1904. 

^ Kirk, T. W., N. Z. R. 348, 1906. 

8 Potebnia, A., Ann. Myc. 8: 58, 1910. 

' Scott, W. M. and Rorer, J. B., B. P. I. B. lU: 1909. 

8 Scott, W. M. and Quaintance, A. C, F. B. 283: 14, 1907. 

9 Clinton, G. P., 111. B. 69: 1902. 

Stewart, F. C, N. Y. (Geneva) R. H: 545, 1895. 

1 Scott, W. M. and Rorer, J. B., B. P. I. B. 121: 1908. 

2 Stevens, F. L., N. C. B. 196: 54, 1907. 

3 Ann. Inst. Cent. Amp. Roy. Hong. 3: 167, 1905. 
' Selby, A. D., 0. B. 2U: 445, 1910. 

5 Briesig, Bui. Min. Ag. Ind. & Cen. Rome, 1910. 

6 Miyaki, Bot. Mag. Tokyo 23: 1909. 

' Stewart, F. C, N. Y. (Geneva) B. 328: 1911. 

8 Halsted, B. D., N. J. R. 12: 279, 1891. 

9 7rfem. 19, iL-355, 1890. 

20 Halsted, B. D., N. J. B. 70: 9, 1890. 
" Halsted, B. D., N. J. R. 1^: 355, 1893. 

22 Selby, A. D., 0. B. 105: 222, 1899. 

23 Patterson and Charles, B. P. I. B. 171. 
2^ Diedicke, H., C. Bak. 19: 168, 1907. 

25 Halsted, B. D., N. J. R. 13: 297, 1892; R. 12: 1891. 
28 N. J. R. 15: 331, 1894. 

27 Humphrey, J. E., Mass. R. 10: 231, 1892. 

28 Humphrey, J.E., Zeit. 3: 360, 1893. 
2«Gueguin, B., S. M. Fr. 18: 312, 1902. 
3» Aderhold. R., C. Bak. 6: 620, 1900. 

" Trinchieri, R., Bui. Ort. Bot. R. Univ. Napoli 2: 409, 1909. 

'2 U. S. D. Agr. R. 88. 

" Stewart, F. C, (Geneva) R. 15: 456, 1896. 

* See footnote, page 53. 
666 



BIBLIOGRAPHY OF FUNGI IMPERFECTI 667 

3" U. S. Dept. Agr. R. 87. 
" Chester, F. D., Del. R. 5: 75, 1892. 
3« Selby, A. D., 0. B. 92: 233, 1898. 
" Lewis, C. E., Sc. 31: 752, 1910. 

38 Lewis, C. E., Me. B. 170: 1909. 

39 Hiilsted, B. D., N. J. B. 91: 1892. 

« McAlpine, Dept. Agric. Melbourne, 132, 1899. 

^' McAlpine : Fungi of the Vine in Australia. 

*2 Frank, Zeit. 3: 28, 1893. 

" Prillieux and Delacroix, B. S. My. Fr. G: 178, 1890. 

'* Rostrup, E., Zeit. I^: 195, 1894. 

« Manns, T. F., Sc. 32: 726, 1910. 

« Manns, T. F., Mycologia 1: 28, 1911. 

« Bos. Zeit. 16: 257, 1906. 

« Quanjer, Zeit. 17: 259, 1907. 

« Rostrup, E., Zeit. 4: 322, 1894. 

^a Rostrup, E., Tid. f. Landok. R. 5: 11, 330, 1891. 

" Kirk, T. W., New Zealand, D. Ag. R. 13: 410, 1905. 

^2 Klebahn, H., Zeit. 20: 1, 1910. 

" Fron, G., Bull. Trim. Soc. Myc. France 25: 66. 

^^ Halsted, B. D., N. J. B. 76: 25, 1890. 

" Stewart, F. C, N. Y. (Geneva) B. 179, 1900. 

6« Arthur, J. C., N. Y., (Geneva) R. 3: 383, 1884. 

" Deidicke, H., Ann. Myc. 9: 8, 1911. 

^« Steward, F. C., Rolfs, F. M., and Hall, F. H., N. Y. B. 191: 298, 1900. 

59 Cordlcy, A. B., Ore. Bui. 60: 1900. 

6« Paddock, W., N. Y. (Geneva) B. 163: 203, 1899. 

81 Eriksson, Zeit. 1: 29, 1891. 

82 Halsted, B. D. and Fairchild, D. G., J. Myc. 7: 1891. 

83 AUescher, A., Zeit. 5: 276, 1895. 
8" Reed, H. S., Mo. B. 69: 1905. 

8s Linhart, Zeit. 5: 92, 1895. 

88 Stoneman, B., Bot. Gaz. 26: 1898. 

8^ Thaxter, R., Ct. R. 13: 163, 1889. 

88 Ducomet, Ann. I'ecole Nat. d'Agr, d. Rennes 24, 1909. 

89 Agr. Soc. 8: 292, 1894. 

'" Williams, T. A., S. Dak. B. 29: 1891. 

'1 Miyake, I., Phytopath. Inst. Agrikult. Abt. der Univ. Tokyo, 1909. 

" Bubak, F., Zeit. Land. Ver. Oe. 18: 502, 1910. 

" Chester, F. D., Del. R. 40, 1902. 

'' Edgerton, C. W. La. B. 126: 194. 



668 THE FUNGI WHICH CAUSE PLANT DISEASE 

'5 Scott, W. M. and Rorer, J. B., B. P. I. B. 121: Dt. 5, 1908. 
^9 Chester, F. D., B. Torr. Bot. Club, IS: 373. 
" Paddock, W., N. Y. (Geneva) B. 185: 1900. 
'8 Peck, C. H., R. N. Y. Mus. Nat. Hist. 1881. 
" Atwood, Proc. A. A. A. S. 47; 413, 1898. 
«" Clinton, G. P., lU. B. 69: 192, 1902. 
" Paddock, W., Science 8: 596. 
«'^ Shear, C. L., Sc. 31: 748, 1910. 
^^ Mangin, L., Jour. d'Agric. Pratique, 1901. 
«^ Griffon and Maublanc, B. S. Myc. Fr. 26: 3. 

«5 GUssow, H. T., Zeit. 20: 406; 1909 also Jour. Roy. Hort. Soc. (Lon- 
don) 222, 1908. 
86 B. S. My. Fr. ^L-75, 1895. 

8' Stewart, F. C. and Eustace, H. J., N. Y. (Geneva) B. 226: 1902. 
88 Stevens, F. L. and Hall, J. G., N. C. B. 196: 1907. 
8» O'Gara, P. J., Phyto. 1: 100, 1911. 
'0 Viali and Ravez, Rev. d. Vit. 197, 1895. 
" Van Hook, J. M., 0. B. 173: 1906. 

92 Kruger, F., C. Bak. 1: 620, 1895. 

93 Bolthauser-Aurisweil, H., Zeit. 1: 135, 1891. 
9^ Porto Rico, R. 397, 1904. 

95 Clinton, G. P., Ct. R. 326, 1903. 

99 Bolthauser, H., Zeit. 8: 263, 1898. 

9' Dudley, W. R., N. Y. (Cornell) B. U: 182, 1889. 

98 Stevens, F. L., Bot. Gaz. U: 241, 1907. 

99 Stewart, F. C, French, G. T. and Wilson, J. K., N. Y. (Geneva) B. 
305: 395, 1908. 

'o" Laubert, R., Arb. K. Gesund. Biol. Abt. 3: 441. 
'01 McAlpine D., Melbourne Dept. of Agric. 132, 1899. 
i«2 Prillieux and Delacroix, B. S. My. Fr. 9: 275, 1893. 
'«3 Burrill, T. J. and Barrett, J. T., 111. B. 133: 1909. 
'"4 Barrett, J. T., Sc. 27: 212, 1908. 
•05 Stevens, F. L. and Hall. J. G., N. C. R. 31: 38, 1909. 
10" Smith, E. F. and Hedges, F., Sc. 30: 60, 1909. 

107 Howard, A., Ann. Bot. 15: 683, 1901. 

108 Pole, J. B. Evans, Trans. D. Agr. Soc. B. 4: 1910. 

109 Butler, E. J., Pusa Agr. Reas. B. 9: 1908. 
"0 Clendenin, I., Bot. Gaz. 21: 92, 1896. 

111 Munch E. and Tubeuf, C, Nat. Zeit. f. For. u. Land. 8: 39, 1910. 

112 Cavara, F., Zeit. 4.- 109, 1894. 

1" Pammel, L. H., la. B. 13: 67, 1891. 



BIBLIOGRAPHY OF FUNGI IMPERFECTI 669 

* Agr. Jour. 9: 135, 1896. 

s Taft, L. R., Mich. Bui. 83: 1892. 

8 Cavara, F., Zeit. 3: 23, 1893. 

' Mangin, L., E. S. R. 10: 452, 1898. 

8 B. Soc. Myc. Fr. 15: 108. 
i« Humphrey, J. E., Mass. R. 7: 1889. 
20 Patouillard and Lagerheim, B. S. My. Fr. 136, 1892. 
" McCarthy, G., N. C. B. 98: 151, 1894. 
•" Chester, F. D., Bull. Torr. Bot. CI. 372, 1891. 
'' N. Y. (Geneva) B. 51: 137, 1893. 
2" Duggar, B. M., N. Y. (Cornell) B. 132: 256, 1897. 
" Humphrey, J. E., Mass. R. 231, 1891. 
26 Rogers, S. S., Cal. B. 208: 1911. 
" Halsted, B. D. N. J. R. 95, 294. 
2« Selby, A. D., 0. B. 73: 1896. 

-3 Chittenden, F. J., Jour. Hort. Soc. London 35: 216. 
3" Beach, S. A., N. Y. (Geneva) R. 11: 557, 1893. 
31 Salmon, R., Econ. Myc. 1908. 
3= Stewart, F. C, N. Y. (Geneva) R. 455, 1896. 
S3 Spaulding, P., B. P. L Cir. 35: 1909. 

34 Jaczewski, A., Zeit. 10: 340, 1900. 

35 Hall, C. J. J. von, Ann. Myc. 1: 503, 1903. 

36 Sturgis, W. C, Conn. State R. 21. 

37 Selby, A. D., Ohio B. 79: 1897. 

38 Kirk, T. W., N. Z. D. Agr. 157, 1907. 

39 Stone, G. E., and Smith, R. E., Mass. R. 67, 1897. 

40 Delacroix, G., B. S. My. Fr. 19: 353, 1903. 
" Scribner, F. L., Tenn. B. 4- 1891. 

« Pierce, N. B., V. P. P. B. 2: 170, 1892. 
" Viala & Pacottet, Rev. de Vit. 1904. 

44 Grossenbacher, J. G., N. Y. (Geneva) T. B. 9: 1909. 

45 Brizi, U., Zeit. 6: 65, 1896. 

46 Paddock, W., N. Y. (Geneva) B. 124, 1897. 

47 Burrill, T. J., Agr. Rev. Wash. 97: 1882. 

48 Lawrence, W. H., Wash. Bui. 97: 1910. 

49 Rorer, J. B., Rep. of the Mycologist, Trinidad, 1910. 
60 Cardin, P. P., Cuba Rev. 8: 28. 

6iWehmer, B., Zeit. 11: 193, 1901. 

62 Kirchner, 0., Zeit. 12: 10, 1902. 

63 Linhart, G., Zeit. 12: 281, 1902. 

64 Fulton, H.. R., Sc. 752, 1910. 



670 THE FUNGI WHICH CAUSE PLANT DISEASE 

i«5 Chester, F. D., Del. R. I^: 60, 1891. 

158 Edgerton, C. W., Bot. Gaz. J^5: 403, 1908. 
1" Sorauer, Zeit. 1: 255, 1897. 

168 Laubert, R., Zeit. IJ^: 257, 1904. 

159 Stone, G. E. and Smith, R. E., Mass. R. 10: 69, 1898. 

160 Stewart, F. C., N. Y. (Geneva) R. IJ^: 531, 1895. 
1" Edgerton, C. W., Ann. Myc. 6: 1908. 

i«2 Massee, G., Kew. Bull. 269, 1908. 

163 Commes, Mit d. Kais. Welt. Inst. f. Land., Bramberg, 2: 1910. 

1" Whetzel, H. H., N. Y. (Cornell) B. 239: 1906. 

"5 Whetzel, H. H., N. Y. (Cornell) B. 255: 1908. 

166 Bull. Torr. Bot. CI. 20: 246, 1893. 

16' Harvey, F. L., Me. R. 152, 1893. 

168 Bull. Soc. Myc. D. Fr. 10: 162, 1894. 

169 Stevens, F. L. and Hall, J. G., Zeit. 19: 65, 1907. 
i™Hume, H. H., Fla. B. 53: 171, 1900. 

1" Rolfs, P. H., B. P. I. B. 52: 1904. 

1" Hume, H. H., Fla. B., 7J^: 1904. 

1" Smith, R. E., Cal. Cult. 1911. 

1'" Edgerton, C. W., Sc. 31: lYJ, 1910. 

1" Lewton-Brain, L., Hawaii Sugar Planters Assn. Bui. 8: 1908. 

1^6 Stevens, F. L., N. C. R. 33: 71, 1911. 

1" Selby, A. D. and Manns, T. F., 0. B. 203: 187, 1909. 

1^8 Bain, S. M. and Essay, S. H., Tenn. B. 75: 1906. 

179 Bain, S. M. and Essay, S. H., J. Myc. 12: 192, 1906. ' 

180 Bain, S. M. & Essay, S. H. Sc. 22: 503, 1905. 

181 Barre, H. W., S. C. B. 153: 1910. 

182 Southworth, E. A., J. Myc. 6: 46, 1890. 

18' Hedgcock, G. G., Mo. Bot. Card. R. 153, 1905. 

18* Stone, G. E. and Smith, R. E., Mass. R. 11: 152, 1898. 

185 Smith, R. E., Bot. Gaz. 27: 203, 1899. 

186 Stewart, F. C, N. Y. (Geneva) B. 179: 105, 1900. 

187 Noack, F., Zeit. 11: 202, 1901. 

188 Halsted, B. D., N. J. R. 17: 410, 1896. 

189 Noack, F., Zeit. 9: 4, 1899. 

190 Atkinson, G. F., N. Y. (Cornell) B. 61: 302, 1893. 

191 Southworth, E. G., J. Myc. 6: 171, 1891. 

192 Edgerton, C. W., La. B. 120: 1910. 

193 Jones, L. R., and Giddings, N. J., Vt. R. 19: 235, 1907. 
19* Raciborski, Zeit. 8: 66, 1899. 

196 Vuillemin, P., B. Sc. M. Fr. 12: 33, 1896. 



BIBLIOGRAPHY OF FUNGI IMPERFECTl 671 

"6 Reed and Cooley, A., Va. 115, 1909-10. 

'" Shear, C. L., B. P. I. B. 110: 1907. 

"8 Wolf, F. A., Neb. R. 21: 69, 1908. 

193 Pierce, N. B., V. P. P. B. 20: 1900. 

^oo Wagner, F. and Sorauer, P., Zeit. 8: 256, 1898. 

=01 Jaczewski A., Zeit. 11: 203, 1901. 

202 Smith, R. E., et al, Cal. B. 191: 73, 1906. 

203 Lewis, C. E., So. 31: 752, 1910. 

204 Butler, E. J., India D. Agr. 2: 8, 1909. 

205 Stewart, F. C. and Eustace, H. J., N. Y. (Geneva) R. 20: 146, 1902. 
208 Pammel, L. H., la. B. 13: 61, 1891. 

207 Fairchild, D. G., J. Myc. 7: 249, 1893. 

208 Arthur, J. C., N. Y. (Geneva) R. 6: 347, 1887. 

209 Geneva R. 8: 293. 

210 Pammel, L. H., la. B. 15: 62, 1891. 

211 Brooks, C., Bull. Torr. Bot. CI. 35: 423, 1908. 

212 Brooks, C., N. H. B. lU: 116, 1909. 

213 Constantin, Rev. Gen. d. Bot. 6: 289, 1894. 

214 Massee, G., Gard. Chron. July 23, 1898. 

215 Oudemans, C. R. Acad. Roy. Sc. d. Pays.-Bas. Jan. 1897. 
21" Sturgis, W. C., Ct. (New Haven) R. 20: 263, 1896. 

21' Thaxter, R., Ct. R. 81, 1890. 

218 Frank, Ber. d. Bot. Ges. 16: 280. 

219 Sturgis, W. C, Ct. State. Sta R. 20: 266, 1896. 

220 Arthur, J. C, Ind. B. 65: 1897. 

221 Arthur, J. C, Ind. B. 39, 1892. 

222 Sturgis, W. C, R., Ct. R. 15: 153, 1891. 

223 W. Va. B. 2: 1897. 

224 Duggar, B. M., N. Y. Cornell B. 163: 359, 1899. 

225 Griffon and Maublanc, B., S. M. d. Fr. 26: 132, 1910. 
22« Magnus, P., Ver. d. Gas. lux Natur freunde. 

227 Brizi, U., Ric. Lab. Chem. Agr. Sc. Milano 3: 169. 

228 Thom, C, B. B. Animal Industry. 

229 Heald, F. D., Neb. D. 103: 1907. 

230 Stewart, F. C. and Hodgkiss, H. E., N. Y. (Geneva) T. B. 7: 1908. 

231 Smith, R. E., Bot. Gaz. 29: 395, 1900. 

232 Brizi, U., C. Bak. 3: 141, 1897. 

233 Ward, H. M., Ann. Bot. 2: 319, 1888. 

234 Istvanffi, G., Ann. L'Inst. Cent. Amp. Roy. Hong. 1905. 

235 Kean, A. L., Bot. Gaz. 15: 8, 1890. 
238 Wehmer, C, Zeit. J^: 204, 1894. 



672 THE FUNGI WHICH CAUSE PLANT DISEASE 

23' Humphrey, J. E., Mass. R. 1892: 219. 

"8 Jones, L. R., Vt. R. 5: 141, 1892. 

"9 Bailey, L. H., N. Y. (Cornell) B. 96: 387, 1895. 

2« Stone, G. E. and Smith, R. E., Mass. B. 69: 1900. 

2" Brooks, F. T., Ann. Bot. 22: 479, 1908. 

2^2 Kisshng, Hedwegia 28: 227, 1889. 

2" Reidemeister, Ann. Myc. 7: 19, 1909. 

24" Wulff, T., Ark. Bot. 8: 18, 1909. 

2« Bos. J. R., Zeit. 8: 263, 1898. 

2« Bureau Plant Industry, B. 171. 

24' Fawcett, H. S. and Burger, 0. F., Mycologia 3: 151, 1911. 

2« Behrens, J., Zeit. 3: 89, 1893. 

2« C. Bak. 6: 625, 1900. 

25" Clinton, G. P., Ct. R. 1905: 274. 

2" Salmon, Econ. Mycol. 1909: 98. 

252 Briosi, G. and Farneti, R., Atti. Inst. Bot. Univ. Pavia 8: 4. 

2" McAlpine, Fungus Diseases Citrus, Austral, 77. 

2" Delacroix, G., B. S. M. Fr. 19: 128. 

2" Fawcett, G. L., P. Rico R. 1909: 35, 1910. 

256 Van Hook, J. M., N. Y. (Cornell) B. 219: 1904. 

2" Rankin, W. H., Spec. Crops, N. S. 9: 349, 1910. 

258 Gueguen, F., Bui. Tri. Soc. Myc. France, 22: 254. 

2M Gueguen, F., C. R. Soc. Biol. Paris 68: 221. 

26" Craig, J. and v. Hook, J. M., N. Y. (Cornell) B. 207: 199, 1902. 

2" Eustace, H. J., N. Y. (Geneva) B. 227: 367, 1902. 

2" Aderhold, R., C. Bak. 5: 552, 1899. 

2«3 Twaroff, K. S., Zeit. IJ^: 36, 1904. 

2"'' Patterson, F. W., Sc. 31: 756, 1910. 

2«'5 Constantine, J. A. Dufour, L., Zeit. 3: 310, 1893. 

2«6 Atkinson, G. F., Bot. Gaz. 15: 166, 1890. 

2" Atkinson, G. F., 0. E. S. B. 33: 309, 1896. 

268Thaxter, R., Ct. R. U: 98, 1890. 

2«9 Porto Rico R. 1903: 449. 

2"> Chittenden, F. J., Card. Chron. 3: 277. 

2'i Metcalf, H., S. C. B. 121: 1906. 

2" Fulton, H. R., La. B. 105: 1908. 

2" Metcalf, H., Sci. 25: 264, 1907. 

27< Smith, E. F., J. Myc. 7: 91, 1892. 

2" Magnus, P., Ber. d. deut. Bot. Ges. 28: 26, 1910. 

2« Zeit. 5: 335. 

2" Fetch, T., Circ. Roy. Bot. Card. Ceylon, Nov. 1909. 



BIBLIOGRAPHY OF FUNGI IMPERFECTI 673 

"« Petri, L., Mo. Gior, Bot. Ital. 582, 1803. 

"» Porto Rico R. 398, 1904. 

=»« Cavara, F., Zeit. 3: 24, 1893. 

=8' Smith, R. E. and Butler, 0., Cal. B. 200: 1908. 

»" Fawcett, H. S., Fla. R. 46: 1909. 

2" Swingle, W. T. and Webber, H. J., V. P. P. B. 8: 1896. 

2" Cal. R. 297, 1892-3. 

2«5 Aderhold, R., Zeit. 6: 72, 1896. 

2«« Arthur, J. C, Ind. B. 19: 8, 1889. 

2" Penzig, Studi Bot. Lugli Agrunii, 1887. 

=«8 Scribner, F. L., Torr. Bull. 13: 181, 1886. 

2«9 Fawcett, Fla. R. 42, 1909. 

=»« Fawcett, Fla. R. 46, 1907. 

291 Fawcett, Mycologia, 2: 245, 1910. 

292 Chester, F. D., Del. R. 8: 60, 1895. 

293 Pammel, L. H., la. B. 23: 919, 1893. 
29" Sturgis, W. C, Ct. R. 20: 269, 1896. 
295 Johnson, E. C, Sc. 31: 792, 1910. 

299 Johnson, E. C, Phytopy. 1: 1911. 

297 Farraris, T., Ann. Myc. 7: 283, 1909. 

298 Orton, W. A., Sc. 21: 503, 1905. 

299 Trelease,"W., D. Agr. R. 129, 1886. 

300 Prillieux and Delacroix, B. S. M. Fr. 7; 218. 

301 Butler, 0., Ann. Bot. 25: 130, 1911. 

3«2 Aderhold, R., Arb. d. biol. Abt. f. land, u for. Gesund II, 519, 1902. 
3«3 Karchner, 0., Zeit. 2: 324, 1892. 
^"^ Sorauer, P., Zeit. 8: 283, 1898. 

305 Bos. J. R., Zeit. 13: 87, 1903. 

306 Reed, H. S. and Cooley, J. S., Va. R. 78, 1911. 

307 Pammel, L. H., King, C. M. and Bakke, A. L., la. B. 116: 1910. 

308 Harvey, F. L., Me. R. 95, 1894. 

309 Thaxter, R., Ct. R. 1889. 

310 Johnson, T., Econ. Proc. Roy. Dublin Soc. 1: 345, 1907. 

311 Appel and Laubert, Ber. d. deut. Bot Ges. 23: 218, 1905. 

312 Chnton, G. P., Ct. State R. 357, 1907. 

313 Aderhold, Zeit. 6: 72, 1896. 

3" Aderhold, R., Arb. K. Ges. Biol. Ab. 3: 439. 

315 Jensen, C. N. and Stewart, V. B., Phyto. 1: 120, 1911. 

318 Patterson, F. W., Torrey Bull. 37: 205, 1910. 

317 Thaxter, R., Ct. R. 13: 158, 1889. 

318 Miyake, Ann. Bot. 3: 1889. 



674 THE FUNGI WHICH CAUSE PLANT DISEASE 

3" Sturgis, W. C, Ct. R. 20: 276, 1896. 

320 Collinge, W. E., R. I. Econ. Biol. Birmingham. • 

'21 Walkoff, K., Zeit. 12: 283, 1902. 

'" Atkinson, G. F., Bot. Gaz. 16: 62, 1891. 

'23 Griffin, H. H., Col. B. 62: 1901. 

"" Ga. R., 351, 1900. 

'" New South Wales Dept. Agric. Rept. 1893. 

328 Harter, L. L., Mycologia 3: 154. 

'" Sturgis, W. C., Ct. R. 19: 186, 1895. 

328 Behrens, J., Zeit. 2: 327, 1892. 

329 Dorsett, P. H., V. P. P. B. 23: 1900. 
"« Halsted, B. D., N. J. B. 76: 1890. 

331 Stevens, F. L. and Hall, J. G., Bot. Gaz. 47: 409, 1909. 

332 Rolfs, P. H., Fla. B. 47: 124, 1898. 

333 Jones, L. R., Vt. B. 72: 16, 1899. 

334 Jones, L. R. Vt. R. 10: 45, 1896. 

335 Jones, L. R. Vt. R. 9: 79. 

336 Galloway, B. T., Agric. Science 7: 377, 1893. 

337 Brocq-Rousseau, D., B. Soc. Nat. Agr. France, 67: 271. 

338 Jones, L. R., and Grant, Bull. Tor. Bot. Club, 24: 257, 1897. 
33^ Barre, H. W., S. C. B. 153: 1910. 

'"o Fawcett, H. S., Fla. B. 106: 1911. 

3" Beach, S. A., N. Y. (Geneva) B. 125: 1897. 

342 Bioletti, F. T., Cal. R. 235, 1895. 

3" Pierce, N. B., Myc. 7: 66, 232, 1892. 

344 Earle, F. S., Div. Pom. B. 5: 27, 1897. 

3« Jones, L. R. and Morse, W. T., Vt. R. 18: 271, 1905. 

346 Bubak, F., Ber. d. deut. Bot. Gez. 28: 533, 1910. 

347 Lagerheim, G. and Wagner, G., Handloch Tid. 426, 1903. 

348 Sturgis, W. C, Ct. R. 20: 273, 1896. 

349 Tyron, H., Rept. Dept. Agric. and Stock. Queensland 89: 1907. 

350 Atkinson, G. F., N. Y. (Cornell) B. 49: 314, 1892. 
3" Scribner, F. L., U. S. D. Agr. R. 117, 1886. 

3" Duggar, B. M., N. Y. (Cornell) B. 163: 352, 1899. 

3" Selby, A. D., 0. B. 105: 232, 1899. 

354 Raciborski, M., Zeit. 8: 66, 1898. 

3" Chester, F. D., Del. R. 95, 1889. 

35^ Fairchild, D. G., U. S. D. Ag. R. 429, 1889. 

3" Halsted, B. D., N. J. R. 397, 1896. 

358 Atkinson, G. F., Am. Flor. 8: 723, 1893. 

359 Zimmermann, A., C. Bak. 8: 221, 1902. 



BIBLIOGRAPHY OF FUNGI IMPERFECTI 675 

MO McAlpine, D., J. Dept. Agr. Victoria, 801, 1902. 
"1 Edgerton, C. W., Phytop. 1: 12, 1911. 
"2 Marchal, E., Bui. Agr. Brussels 17: 4. 
303 Zimmerman, A., C. Bak. 7: 145, 1901. 
3" Massee, G., Kew Bui. 19, 1898. 
3«5 Sheldon, J. L., Torreya 8: 141, 1908. 
'«« South, F. W., W. Ind. B. 11: 83, 1911. 
=>" Stevens, F. L., and Hall, J. G., J. Myc. 13: 94, 1907. 
'*^ Appel and Wallenweber, Arb. d. Kais. Biol. Ans. f. Land. u. Frst. 8: 
Heft 1. 

="'3 Cook, M. T., Sc. 31: 751, 1910. 

^'^ Aderhold, Zeit. 11: 65, 1901. 

"1 Aderhold, R., C. Bak. 5: 523, 1899. 

3" Pound and Clements, Neb. Bot. Sur. 3: 12, 1893. 

='' Cook, M. T., Del. Bull. 93: 1911. 

"^ Osterwalder, A., C. Bak. 13: 207, 1904. 

"5 Morse, W. T. and Lewis, C. E., Maine B. 185: 1910. 

3™ Smith, E. F., Sc. 31: 755, 1910. 

"^ Briosi, Att. d. R. Acad. d. Lincei Roma Ser. 2: 3. 

"8 Proc. W. N. Y. Hort. Soc. 43: 9, 1898. 

"9 Sheldon, J. L., Neb. R. 23, 1904. 

'80 Smith, E. F., V. P. P. B. 17: 1899. 

'81 Atkinson, G. F., Ala. B. 4I: 19, 1892. 

'82 Orton, W. A., V. P. P. B. 27: 1900. 

'8' Higgins, B. B., N. C. R. 32: 100, 1909. 

'84 Chester, F. D., Del. R. 5.- 89, 1890. 

'85 Detmers, F., Ohio B. 44: 147, 1892. 

'89 von Hall, Ber. deut. Bot. Gez. 21: 2. 

'87 Schikorra, G., Diss. 1906. 

'88 Butler, Mem. Dept. Agr. India,^Bot. Ser. 2: 9, 1910. 

'89 Smith, E. F., Proc. A. A. A. S. 190, 1895. 

'«» Smith, E. F., Proc. A. A. A. S. 43: 289, 1894. 

'91 Bubak, Fr., Ber. d. deut. Bot. Ges. 29: 73. 

'" Smith, R. E., Mass, B. 79, and Mass. R. 57, 1902. 

'" Reed, H. S., Sc. 23: 751, 1906. 

»94 Stone, G. E., and Smith, R. E., Mas. B. 69: 1900. 

'« Manns, T. F., 0. B. 229: 1911. 

89« Smith, E. F. and Swingle, D. B., B. P. I. B. 55: 1904. 

'" Stewart, F. C, N. Y. (Geneva) B. 101: 85, 1896. 

'=8 Wehmer, C, C. Bak. 3: 727, 1897. 

'5^ Clinton, G. P., 111. B. 4O: 139, 1895. 



676 THE FUNGI WHICH CAUSE PLANT DISEASE 

«o Oven., Lanchv. Jahr. 3J^: 489, 1905. 

401 Massee, Gard. Chron. Ser. 3: 17, 707. 

«2 Smith, R. E., Cal. B. 175: 8, 1906. 

«3 Bolley, H. L., N. D. B. 50: 1901. 

«4 Harter, L. L., Sc. 30: 934, 1910. 

«5 Ostervvalder, A., Land. Jahr. Schw. 2 4: 247. 

«« Galloway, B. T., Amer. Gard. 17: 518, 1896. 

4«' Smith, R. E., Mass. B. 79: 1902. 

«8 Stewart, F. C., N. Y. (Geneva) B. m: 219, 1899. 

^"^Sturgis, W. C, Ct. R. 21: lib, 1897. 

41" Chifflat, J., Jour. Soc. Nat. Hort. France, 4: Ser. 8, 348. 

411 Pollock, J. B., Sc. 31: 638, 1910. 

412 Prillieux and Delacroix, C. R. 131: 961, 1900. 

413 N. S. R. Wales, 93. 

414 Doherty, M. W., Bot. Gaz. 30: 400, 1900. 

415 Rept. Mo. Bot. Gard. 9: 159, 1898. 
4iSSci. ;4.-899, 1901. 

4'^ Duggar, B. M., N. Y. (Cornell) B. 163, 1899. 
418 Stone and Smith, Mass. R. 67: 1897. 
413 Heald, F. D., Phytop. 1: 103, 1911. 

420 Gussow, H. T., Zeit. 16: 135, 1906. 

421 Stevens, F. L. and Wilson, W. G., Sc. 33: 943, 1911. 

422 Scholz, E., Verh. K. K. Zool. Bot. Ges. Wien, 47: 541. 

423 Selby, A. D., 0. B. 92. 

424 Bertoni, W. S., Rev. Agr. Cien. Apt. Paraguay 1: 211. 

425 Earle, F. S., Ala. B. 108: 1900. 
420 Stout, A. B., Sc. 33: 156, 1911. 

427 Klebahn, H., Jahr. d. Hamb. Wiss. Ans. 22. 

428 Shear, C. L., Bull. Tor. Bot. Club 3^: 305, 1907. 

429 Atkinson, G. F., Bot. Gaz. 18: 16, 1893. 
43oPammel, L. H., Tex. R. 2: 61, 1889. 

431 Pammel, L. H., B. Tex. 4: 1888. 

432 Shear, C. L. and Miles, G. F., B. P. I. B. 102: 39, 1907. 

433 Galloway, B. T., and Woods, A. F., Y. B. 248, 1896. 

434 Stewart, F. C. and Blodgett, F. H., N. Y. (Geneva) B. 167: 283. 

435 Johnston, T. H., Agr. Gaz. N. S. Wales 21: 563. 

436 Stevens, F. L. and Hall, J. G., N. C. R. 31: 72, 1909. 

437 Swingle, W. T., and Webber, H. J., V. P. P. B. 8: 32, 1896. 
"8 Fulton, H. R., La. B. 101: 1908. 

«» Porto Rico R. U9: 1903. 

440 Arthur, J. C, N. Y. (Geneva) R. 4: 250, 1885. 



BIBLIOGRAPHY OF FUNGI IMPERFECTl 677 

"> Laubert, R., Gartenflora 59: 409, 1910. 
^^2 Chester, F. D. Del, 6:111, 1893. 
^" Peck, N. Y. St. Mus. Nat. Hist. B. 137: 21. 
"^ Bot. Gaz. 54: 231. 
^^5 Sc. 37: 638. 

^« Cordley, Ore. Sta. Bienn. Crop. Kept. & Hort. R. 1911-12, 187: 
1913. 

^" Stone, Ann. Myc. 10: 564, also Melhus, Phytop. 3: 56. 

^^8 Stewart, F. C. N. Y. (Geneva) B. 328, 387. 

^" Ann. Myc. 10: 491. 

«« Gussow, Canada Exp. Farms. R. 1912, 202. 

"1 Ann. Myc. 6: 112. 

4^2 Peck, N. Y. Mus. R. S^; 41. 

«3 Chester, F. D., Del. B. 70: 13. 

«4 Gussow, Zeit. 16: 10. 

<" Heald, F. D., Mycol. 1: 215, 1909. 

«« Wehmer, C, C. Bak. 5; 646, 1897. 

"^ Percival, J., Jour. Southeast Agr. Col. Wye, 81: 1902. 

«8 Chifflat, J., Jour. Soc. Nat. Hort. France, Ser. 4, 8, 348. 

«« Arthur, J. C, Ind. B. 19: 5, 1889. 



SOME OF THE MOST USEFUL BOOKS 

1. Buller Researches on Fungi. 

2. A. De Bary: Comparative Morphology & Biology of the Fungi Myce- 

tozoa & Bacteria. Clarendon Press, 1887. 

3. G. Delacroix and A. Maublanc: Maladies des Plantes Cultiv^es. 

J. B. BailUere & Fils, 1909. 

4. Ducomet: Pathologie Veg^tale, Chas. Amat, 1908. 

5. B. M. Duggar, Fungous Diseases of Plants. Ginn & Co., 1909. 

6. A. Engler: Syllabus der Pflanzcnfamilicn, Gebriider Borntrseger, 

1907. 

7. Engler and Prant: Natlirliche Pflanzenfamihen, Wm. Engelmann, 

1897. 

8. W. G. Farlow: BibUographical Index to N, American Fungi, Car- 

negie Inst, of Washington, 1905. 

9. Farlow & Seymour: Host Index of the Fungi of the U. S., Cambridge, 

1888. 

10. A. B. Frank: Die Pilzparasitaren Krankheiten der Pflanzen. Ed. 

Trewendt, 1896. 

11. E. M. Freeman: Minnesota Plant Diseases, Pioneer Press, 1905. 

12. K. Goebel: Outlines of Classification & Special Morphology of Plants, 

Clarendon Press, 1887. 

13. R. Hartig: The Diseases of Trees. 

14. R. Hartig: Lehrbuch d. Pflanzenkrankheiten, JuHus Springer, 1900. 

15. Ideta: Text-book of Plant Diseases, Japanese. 

16. 0. Kirchner: Die Krankheiten und Beschadigungen unserer land- 

wirtschaftUchen Kulturpflanzen. Eugen Ulmer, 1906. 

17. Ernst Kuster: Pathologische Pflanzenanatomie, Gustav Fischer, 

1903. 

18. Franz Lafar: Handbuch d. Technischen Mykologie, Gustav Fischer, 

1904-1907. 

19. Lindau in P. Sorauer: Handbuch d. Pflanzenkrankheiten. Paul 

Parey, 1908. 

20. Lindau and Sydow, Thesaurus Literaturse Mycologicse. 

21. Lotsy: Vortrage tiber botanische Stammesgeschichte, Gustav Fischer, 

1907. 

678 



SOME OF THE MOST USEFUL BOOKS G79 

22. Geo. Massee: Diseases of Cultivated Plants and Trees. Duckworth & 

Co., 1910. 

23. Geo. Massee: Text-book of Fungi, Duckworth & Co., 1906. 

24. E. Prillieux: Maladies des plantes agricoles. 

25. P. A. Saccardo: Sylloge Fungorum, Pa via; R. Friedlander & Sohn 

1882. 

26. Stevens and Hall: Diseases of Economic Plants, Macmillan Co., 1910. 

27. Tubeuf and Smith: Diseases of Plants Induced by Cryptogamic 

Parasites, Longmans, Green & Co., 1897. 

28. L. M. Underwood: Moulds, Mildews and Mushrooms. Henry Holt & 

Co., 1899. 

29. H. Marshall Ward: Disease in Plants. Macmillan & Co., 1901. 

30. Strasburger, Noll, Schenck and Karsten: Text-book of Botany, 1908. 

31. F. D. Chester: Manual of Determinative Bacteriology. Macmillan & 

Co., 1901. 

32. H. W. Conn: Agricultural Bacteriology. P. Blakiston's Son & Co., 

1909. 

33. A. Fischer: Vorlesungen ueber Bakterien, Gustav Fischer, 1903. 

34. C. Flugge: Die Mikroorganismen. F. C. W. Vogel, 1896. 

35. E. 0. Jordan: General Bacteriology. W. B. Saunders Co., 1908. 

36. J. G. Lipman: Bacteria in Relation to Country Life. Macmillan & 

Co., 1908. 

37. W. Migula: System der Bakterien. Gustav Fischer, 1897. 

38. Miquel et Cambier: Traits de Bacteriologie Pure et Appliqu6e. 

Masson et Cie, 1902. 

39. E. F, Smith: Bacteria in Relation to Plant Diseases. Carnegie In- 

stitution, Sept., 1905. 

40. A. Lister: The Mycetozoa, 1895. 

41. Geo. Massee: Monograph of the Myxogastres, 1892. 

42. H. Macbride: North American Slime-Moulds. Macmillan, 1899. 

43. Rostafinski: Sluzowce Monografia, 1875. 

44. Torrend: Les Myxomyc6tes. Brotevia 7: 5, 177; pi. 1-9, also sepa- 

rate, 1908. 

45. Plowright, British Uredinese & Ustilaginese. 

46. Salmon, Monograph of the Erysiphacese. 

47. Clinton, G. P., North American Flora, Ustilaginales. 

48. Murrill, W. A., North American Flora, Polyporacese, etc. 

49. Arthur, J. C, North American Flora, Urediniales. 

50. Atkinson, G. F., Mushrooms. 

51. Clements, The Genera of Fungi. 

52. Ellis and Everhart, North American Pyrenomycetes. 



680 THE FUNGI WHICH CAUSE PLANT DISEASE 

'53. Rabenhorst, Kryptogamen Flora von Deutschland. 
64. Bancroft, K., Handbook of the Fungous Diseases of West Indian 
Plants, 1910. 

55. Hartig, The Diseases of Trees, Trans, by Sommerville. 

56. McAlpine, Rusts of AustraUa. 

57. Jaczewski, A. A., Phytopathology (Russian). 

58. Noel Deer: Sugar Cane. Norman Rodger, Manchester, 1911. 

59. Klebahn, H., Die Wirtwechselnden Rostpilze, 1894 

60. Sydow, Monographia Uredinearum, 1904. 

61. Holway, E. W. D., North American Uredineee, 1905. 

62. Seaver, North American Flora, 3: Pt 1. 

63. Viala, R., Les Maladies de la Vigne. 

64. P. Harlot, Les Uredin^es, Paris, 1908. 

Periodicals of use to the Phytopathologist 

Phjiiopathology. 

Annales Mycologici. 

Centralblatt fur Bakteriologie U. Paristenkunde II. Abt. 

HoUrung's Jahresbericht u. d. Gebeit der Pflanzenkrankheiten. 

■Experiment Station Record. 

Zeitschrift fiir Pflanzenkrankheiten. 

Rivista di Patologia vegetale. 

Hedwigia. ' 

Mycologia, formerly Journal of Mycology. 

Practische Blatter fiir Pflanzenschutz. 

Just's Botanischer Jahresbericht. 

Bulletin Trimestriel de la Societie Mycologique de France. 

For Bibhographies of special articles, see pages 53, 109, 288, 466, 666. 



GLOSSARY 



A, privative. Signifying without. 

Acervulus (i). A small cluster, tuft of mycelium bearing spores. 

Acicular. Slender or needle-shaped. 

Acrogenous. Growing at the apex. 

Acropetal. Produced in a succession towards the apex. 

Adnata. Attached the whole length. 

^ciospore. .fficidiospore. A spore formed in an secium. 

JEciuta (a), .fficidum (a). A special form of sorus in the Uridinales. 

Aerial. Living above the surface of the ground or water. 

Aerobic. ASrobiotic. Requiring oxygen. 

.ZEthalioid. Like an sethalium. 

.^thalium (a). A compound sporiferous body formed from a large 
combination of plasmodia. 

Agglutinated. Agglutinate. Glued together. 

Aggregated. Aggregate. Collected together. 

AUantoid. Sausage-shaped, crescent-shaped with rounded ends. 

Alveola (ae). Cavities or pits on the surface. Alveolate. Pitted like 
a honeycomb. Alveolar. Pertaining to or resembling Alveolae. 

Amoeboid. Like an amoeba, exhibiting creeping movement by pseudo- 
podia. 

Amorphous. Shapeless. 

Amphigenous. Growing all round an object, not restricted to any par- 
ticular surface. 

AmpuUiform. Swollen out. Flask-shape. 

Anastomosing. Uniting and forming a network. 

Angiocarpous. Invested by some covering. 

Annulate. Ring-shaped or with a ring. 

Annulus. A ring-like portion of the ruptured marginal veil, after the 
expansion of the pileus. 

Anoderm. Without a skin. 

Antheridium (a). In fungi the male sexual organ. 

Apical. At the point of any structure. 

Apicula. A sharp and short, but not stiff point. 

681 



682 GLOSSARY 

Apogamous. Showing apogamy. 

Apothecium (a). An ascocarp in which the hymenium lies exposed 
while the asci are maturing. 

Appendages. Processes of any kind. 

Appendiculate. Furnished with appendages. 

Appiculate. Furnished with an appicula. 

Appressed. Lying flat for the whole length. 

Appresoria. Organs of attachment of germinating parasites. 

Approximate. Close together, but not united. 

Arachnoid. Like a cobweb. 

Arcuate. Curved. 

Areola (ae). A space marked out on a surface. 

Aristate. Awned. 

Armilla. A bracelet-like frill. 

Armilla-form. Armilla-like. 

Ascigerous. Bearing asci. 

Ascocarp. A sporocarp producing asci. 

Ascogenous. Producing asci. 

Ascogonium. In ascomycetous fungi, the cell or group of cells fer- 
tilized by a sexual act. 

Ascoma. Receptacle and hymenium of the larger fungi. 

Ascopla§m. Protoplasm of the ascus. 

Ascus (i). A large cell in the ascocarp in which spores are developed, 
usually eight. 

Aseptate. Without cross-divisions. 

Asexual. Destitute of male and female organs. 

Asperate. Rough with hairs or points 

Attenuate. Tapered. 

Auriform. Ear-shaped. 

Autoecious. A parasite which runs its whole course on a single host. 

Avellaneous. Drab, hazel, hazel-nut-brown. 

B 

Bacillar. Bacilliform. Rod- or club-shaped. 

Basal. At the base of. 

Basidiospore. A spore acrogenously abjointed upon a basidium. 

Basidium. The mother-cell from which spores are acrogenously 

abjointed. 
Basipetal. Growth in the direction of the base. 
Bay. Reddish brown or chestnut color. 
Biogenous. Growing on living organisms. 



GLOSSARY 683 



Botryose. Racemose. 
BuUate. Blistered or puckered. 
Byssoid. Flax-like or cottony. 



Calcareous. Chalk-white, chalky. 

Campanulate. Bell-shaped. 

Cancellate. Latticed, as in Clathrus. 

Capillitium. Sterile thread-like tubes or fibers, mixed with the spores 

within a sporangium. 
Capitate. Having a head. 
Carbonous. Carbonaceous. Dark colored. Consisting chiefly of sul> 

stances in which carbon predominates. 
Carpogonium (a). Part of a procarp resulting in a sporocarp after 

fertilization. 
Cartilagenous. Hard and tough. 
Castaneous. Chestnut-colored. 
Catenulate. Concatenate. Formed of parts united or linked as in 

a chain. 
Caulicolous. Living on stems. 
Cespitose. Growing in tufts. 

Chlamydospore. A spore having a very thick membrance. 
Chromogenesis. Color production. 
Chromogenic. Chromogenous. Color-producing. 
Ciliate. Fringed with hairs. 
Cilium (a). Vibratile whip-like processes of protoplasm by which 

zoospores and similar bodies move. 
Cinereous. Cineraceous. Ashy. 

Circinate. Circinnate. Coiled into a ring or partially so. 
Circumscissile. Dehiscing as if cut circularly around. 
Cirrhose. Cirrose. Cirrhous. Having a cirrhus or tendril. 
Clathrate. Latticed. 

Clavate. Club-shaped, thickened towards the apex. 
Clypeate. Buckler or shield-shaped, having a clypeus. 
Clypeus. A buckler or shield-shaped tissue around the mouth of a 

perithecium. 
Ccenocyte. A multinucleate cell. 
Collabent. Collapsing. 
CoUiculose. With little round elevations. 
Columella. Sterile axile body within a sporangium. 



684 GLOSSARY 

Columnar. Having the form of a column. 

Compound. Similar parts aggregated into a common whole. 

Con or Com. In Latin compounds signifying with. 

Conchate. Shell-shaped. 

Concolorous. Of one color. 

Confluent. Blended into one. 

Conglobate. Collected into a ball. 

Conidiophore. A sporophore bearmg a conidium. 

Conidiospore. Same as conidium. 

Conidium (a). Dust-like spores usually produced directly from the 

hypha3. 
Conjugation. Union of two like gametes to form a zygote. 
Connate. United. 

Constricted. Drawn together; contracted. 
Context. The flesh of a mushroom and the corresponding substance in 

other pileate fungi. 
Continuous. The reverse of interrupted. 
Convoluted. Convolute. Rolled round. 
Coremium. The name of a genus of fungi, derived from a Greek word 

meaning broom. 
Coriaceous. Leathery. 
Corneous. Of horny texture. 
Cortex. The bark or rind. The peridium of Fungi. 
Cortical. Relating to the cortex. 
Costate. Ribbed. 

Crateriform. Globet or cup-shaped. 
Cristate. Crested. 
Cruciate. Cross-shaped. 
Crustose. Crust-like. 
Cuboid. Resembling a cube. 
Cupulate. With a cupule. 
Cupuliform. Shaped like a small cup. 
Cuticle. The outermost skin. 
Cuticulate. Having a cuticle. 

Cylindric. Cylindrical. Elongated, with a circular cross-section. 
Cyme. Cluster of determinate or centrifugal type, especially a broad 

and flattened one. 
Cyst. A sac or cavity. 
Cystidium (a). Large, one-celled, sometimes inflated bodies, projecting 

beyond the basidia and paraphyses of the hymenium of Agarics. 
Cytolitic. A ferment which dissolves the cell-wall. 



GLOSSARY 685 



Deciduous. Falling in season. 

Decumbent. Reclining with the summit ascending. 

Decurrent. Running down. 

Definite. Precise; of a certain number. 

Dehiscence. The mode of opening. 

Deliquescent. Dissolving or melting away. 

Dendritic. Having a branched apiDearance. 

Dendroid. Tree-like in form, or branching. 

Denticulate. Minutely toothed. 

Depressed. Sunk down, flattened. 

Determinate. Definite. 

Di. Two or double. 

Dichotomous. Forked. 

Dichotomy. Forking in pairs. 

Difiform. Of double form, irregular. 

Diffuse. Widely or loosely spreading. 

Digitate. Fingered: compound. As in the Horse Chestnut leaf. 

Dimidiate. Halved, as when half an organ is so much smaller than the 

other as to seem wanting. 
Disciform. Flat and circular. 
Discoid. Resembling a disk. 
Disculate. Having a disk. 

Dis junctors. Spindle-shaped cellulose connections between conidia. 
Dissepiment. A partition. 
Doliform. Barrel-shaped. 



E, Ex. Privative in Latin compounds. 

Echinulate. Having small prickles. 

Efifuse. Expanded. 

Ellipsoid. ElUpsoidal. Elliptic. Like an ellipse. 

Embedded. Surrounded in. 

Endogenous. Produced within. 

Endophyte. Growing inside another plant. 

Endophytic. As an endophyte. 

Endospores. Spores formed endogenously. 

Endozoic. Living inside an animal. 

Entire. With even margin. 



686 GLOSSARY 

Entomogenous. On insects. 

Enzyme. An unorganized or soluble ferment. 

Epi. In Greek compoimds to mean " upon ". 

Epiphyllous. Growing on leaves. 

Epispore. Outer coat of a spore. 

Epithecium. The surface of the fructifying disk. 

Epixylous. Growing on wood. 

Erumpent. Breaking through. 

Evanescent. Soon disappearing. 

Excipuliform. Wart-like. 

Exospore. The outer covering of the spore. 

Explanate. Spread out flat. 

Exserted. Protruding beyond. 



F 

Facultative. Occasional, incidental as opposed to obligate. 

Falcate. Sickle-shaped. 

Fascicle. A little bimdle. 

Fasciculate. In clusters or bundles. 

Favoid. Like a honeycomb. 

Ferruginous. Ferrugenous. Ferrugineous. Rust-colored. 

Fibrinous. Fibrillose. Furnished with fibers. 

Filamentous. Of free hyphse which are at most loosely interwoven 

but without forming bodies of definite shape and outline. 
Filiform. Thread-shaped. 

Fimbriate. With the margin bordered by long slender processes. 
Fission. Splitting. 
Flabellifonn. Shaped as a fan. 
Flaccid. Limp, flabby. 

Flagellate. Provided with whip-like processes. 
Flagellum (a). Whip-like process of protoplasm of a swarmspore. 
Flavous. Nearly pure yellow. 
Fleshy. Succulent. 

Flexuose. Flexuous. Bent alternately in opposite directions, zigzag. 
Flocci. Locks Uke soft hair or wool. 
Floccose. Bearing flocci. 
Flocculent. Diminutive of Floccose. 
Fluorescence. The property of diminishing refrangibility. 
Fluorescent. Exhibiting fluorescence. 
Foetid. Fetid, stinking. 



GLOSSARY 687 



Foliar. Leafy or leaf-like. On a leaf. 

Foliicolous. On leaves. 

Free. Not adhering. 

Fructicolous. Living on fruit. 

Fruticolous. Living on shrubs. 

Fruticose. Shrubby. 

Fugacious. Soon perishing. 

Fuligineus. Fuliginous. Sooty, or soot-colored. 

Fulvous. Yellow, tawny. 

Fumaginous. Smoky; sooty. 

Furcate. Forked. 

Fuscous. Dusky, too brown for a gray. 

Fusiform. Thick but tapering towards each end. 

Fusoid. Somewhat fusiform. 



Gametangium (a). A differentiated cavity, which produces gametes. 

Gamete. A sexual protoplasmic body. 

Gemma (ae). A young bud. 

Gemmation. Budding. 

Gemmiform. Bud-shaped. 

Gill. The plates or lamella? of an Agaric. 

Glabrous. Without hair. 

Gleba. The gelatinous spore mass in the Phallales. 

Globoid. Rounded. 

Globose. Nearly spherical. 

Glomerate. Agglomerate, collected into heads. 

Granular. Composed of grains. 

Gregarious. Growing in company. Associated but not matted. 

Guttulate. Resembling drops, with drops. 

Gymnocarpous. Naked fruited. 

Gyrose. Curved backward and forward in turn. 



Hamate. Hooked at the tip. 

Haustorium (a). Special branch of a filamentous mycelium serving 

as an organ of attachment and suction. 
Hetercecism. Condition of a heteroecious parasite. 
Hetercecious. Passing its stages on more than one host. 
Heterogamy. With gametes not uniform. 



688 GLOSSARY 

Heteromorphic. Heteromorphous. Variation from normal structure, 
as liaving organs differing in length; dimorphic, 

Hirtose. Hirtus. Hairy; hirsute. 

Hispid. Bristly. 

Hoary. Gray from fine pubescence. 

Host. A plant which nourishes a parasite. 

Hyaline. Colorless or translucent. 

Hyaloplasm. The hyaline matrix or clear non-granular portion of pro- 
toplasm. 

Hymenium (a). An aggregation of spore mother-cells in a continuous 
layer on a sporophore. 

Hymenophore. That part which bears the hymenium. 

Hypha (ae). The thread-like vegetative part of a fungus. 

Hyphoid. Resembling hyphae. 

Hypertrophy. An abnormal enlargement of an organ. 

Hypophyllous. Situated under a leaf. 

Hypopodium (a). The stalk or support. 

Hypothallus. The marginal outgrowth of hyphae often strand-like, 
from the thallus. 

Hypothecium. A layer of hyphal tissue immediately beneath the 
hymenium. 

Hysterioid. Elongated boat-shaped, resembling the genus Hysterium. 



I, n, HI. Symbols for the stages of the rusts, see p. 324, 326. 

Imbricate. Overlapping as the tiles on a roof. 

Immersed. Below the surface. 

Imperforate. Without an opening. 

Incrassation. Thickened growth. 

Indehiscent. Not opening along regular lines. 

Indeterminate. Not terminated definitely. 

Indurate. Hardened. 

Infundibuliform. Shaped like a funnel. 

Innate. Born on the apex of the support. Imbedded. 

Intercalary. Growth which is not apical but between the apex and the 

base. 
Intercellular. Between cells. 
Intracellular. Inside a cell. 
Intramycelial. Within the mycelium. 

Involute. Enwrapped, having the edges of the leaves rolled inwards. 
Irpiciform. Having teeth resembling those in Irpex. 



GLOSSARY G89 

Isabelline. A dirty tawny tint. 

Isogamous. Used for those plants which produce like gametes. 

Isogamy. Conjugation of two gametes of similar form. 



Keeled. Carinate. 



Labyrinthiform. Marked by sinuous lines. 
Lacerate. Torn, or irregularly cleft. 
Lactiferous. Latex bearing. 
Lamella (ae). The gills of Agaricales. 
Lamellate. Made up of thin plates. 
Lamelliform. In the shape of a plate or scale. 
Lamelloid. Resembling lamellse. 
Lageniform. Shaped like a Florence flask. 
Lanceolate. Narrow, tapering to each end. 
Latericious. Lateritious. Brick-red. 
Latticed. Cross-barred. 
Lax. Loose, distant. 

Lenticular. Shaped like a double convex lens. 
Lichenoid. Irregularly lobed as lichens. 
Lignicole. Growing on wood. 
Limonifonn. Lemon-shaped. 
Linear. Narrow, several times longer than wide. 
Lipochrome. A yellow pigment. 
Lobate. Lobed. Divided into or bearing lobes. 
Locule. Loculus. A cell or cavity. 

Lumen. The space which is bounded by the walls of an organ, as the 
central cavity of a cell. 

M 

Macro. Mega. In Greek compounds to signify large. 
Maculicole. On spots. 
Mammiform. Breast-shaped. 

Marginate. Broad-brimmed, furnished with a margin of distinct char- 
acter. 
Matrix. The body on which a Fungus or Lichen grows. 
Malleus. Melleous. Like honey. 



690 GLOSSARY 

Membranous. Membranaceous. Thin and semi-transparent, like a 
fine membrance. 

Medullary. Relating to the pith, pithy. 

Micro. To signify small, little. 

Microsporangium (a). A sporangium which produces microspores. 

Mon. In Greek compounds to signify one. 

Monopodium (a). An axis which continues to grow at the apex in 
the direction of previous growth, while lateral structures of like 
kind are produced beneath it in acropetal succession. 

Monosporic. Bearing one spore. 

Monostichous. In a single vertical row. 

Mucose. Slimy. 

Multi. A Latin element signifying many or much. 

Muricate. Rough with short hard excrescences. 

Muriculate. Diminutive of Muricate. 

Muriform. With cells resembling bricks in a wall, with both longitudi- 
nal and transverse septa. 

Muticous. Muticate. Pointless, blunt. 

Mycelium. Vegetative portion of thallus of fungi composed of one or 
more hyphse. 

Myxamoeba (ae). Swarm-cells with purely amoeboid creeping motion. 

N 

Nodose. Knotty or knobby. 
Nodule. A small knot or rounded body. 



O. A symbol for the pycnial stage of the rusts. 

Ob. As a prefix meaning inversely or oppositely. 

Obese. Excessively fat; fleshy. 

Obligate. Necessary, essential. Comp. Facultative. 

Obsolete. Wanting or rudimentary. 

Ochraceous. Ocher-colored, yellow with a tinge of red. 

Olivaceous. The color of a ripe olive. 

Oogonium. Female sexual organ, containing one or more oospheres. 

Oosphere. Naked mass of protoplasm which, after fertilization, develops 

into the oospore. 
Oospore. Immediate product of fertilization of oosphere. 
Opalescent. Reflecting an iridescent light. 
Operculate. Furnished with a lid. 



GLOSSARY 691 

Operculum. A lid or cover which separates by a transverse hne of 

division. 
Opt. Abbreviation for Optimum. 
Ostiolate. Bearing an ostiole. 
Ostiole. An o])ening or mouth. 
Oval. Broadly elliptic. 

Ovate. Shaped like a longitudinal section of a hen's egg. 
Ovoid. Resembling an egg. 



Pannose. Felt-like. 

Papilla (ae). Soft superficial protuberances. 

Papillate. Having papilte. 

Papilliform. Shaped like a papilla. 

Papilloid. Resembling a small nipple. 

Paraphysate. With paraphyscs. 

Paraphyses. Sterile filaments occurring in the fructification of crypto- 
gams. 

Parasite. An organism living on or in and at the expense of another 
living organism (the host). 

Patellate. Shaped like a patella. 

Patelliform. Like a small dish, circular and rimmed. 

Pedicel. The support. 

Pedicellate. Borne on a pedicel. 

Pellicle. A small skin; a delicate superficial membrane. 

Pellucid. Wholly or partially transparent. 

Penicillate. Like a little brush. Pencil-shaped. 

Perforate. Pierced through. 

Peridium. The outer enveloping coat of a sporangium. 

Periplasm. The protoplasm in the oogonium and the antheridium 
which does not share in conjugation. 

Perithecium. A rounded, oval, pyriform or beaked structure in which 
asci are borne. 

Peritrichiate. With hairs from all of surface. 

Persistent. Remaining till the part which bears it is wholly matured. 

Phycochrome. The coloring matter of brown Algae. 

Phyllogenous. Growing upon leaves. 

Phytogenous. Growing on plants. 

Pileate. Having the form of a cap. 

Pileiform. Pileus-shaped. 

Pileus. Cap. The dome-shaped part of a sporophore. 



692 GLOSSARY 

Pilose. Pilous. Hairy, having soft and distinct hairs. 

Planose. Plane. 

Plasmodiocarp. An asymmetrical sporangium of the Myxogastres. 

Plasmodium. Body of naked plurinucleated protoplasm exhibiting 

amoeboid motion. 
Pleurogenous. Growing from the sides. 
Plexus. A network. 

Plicate. Folded into plaits usually lengthwise. 
Polar. Relating to the poles of an organ. 
Polymorphic. Polymorphous. With several or various forms, variable 

as to habit. 
Polysporic. Many spored. 
Porcelaneous. Like porcelain. 
Poroid. Resembling pores. 
Porose. Containing pores. 
Proliferous. Bearing offshoots. 
Promycelium. Short and short-lived product of tube-germination of 

a spore which adjoins acrogenously a small number of spores 

(sporidia) unlike the mother-spore and then dies off. 
Pseudo. In prefix signifying false, counterfeit, spurious. 
Pulverulent. Powdered, as if dusted over. 
Pulvinate. Cushion-shaped. 
Punctiform. In the form of a point or dot. 
Punctulate. Marked with small points. 
Pustular. Blister-like, bearing blisters. 
Pustule. A pimple or blister. 

Pustuliform. Having slight blister-like elevations. 
Putrescent. Becoming rotten. 
Pycnidium (a). A variously shaped cavity resembling a pyrenocarp 

and containing conidia. 
Pycniospore. Spores borne in pycnia. 
Pycnium. A structure of the Uridinales; see pp. 324-326. 
Pycnosclerotia. Sclerotia bearing pyenidia. 
Pycnospores. Spores from pyenidia. 
Pyriform. Piriform. Resembling a pear in shape. 

R 

Radiate. Spreading from or arranged around a common center. 

Ramicole. Growing on branches. 

Ramose. Branched. 

Receptacle. That part which bears one or more organs. 



GLOSSARY 693 

Reniform. Kidney-shaped. 

Resupinate. Without a pileus. 

Reticulate. Netted, like network. 

Revolute. Rolled back from the margin or apex. 

Rhizoid. A root-like structure. 

Rhizomorph. A root-like branched strand of mycelial hyphse. 

Rhomboidal. Approaching a rhombic outline. 

Rimose. Rimous. Cracked. 

Rostrate. With a beak. 

Rostrum. Any beak-like extension. 

Rufous. Reddish. 

Rugose. Rugous. Covered with wrinkles. 



Saccate. Bag-shaped. 

Saprophyte. A plant living on dead organic substance. 
Sarcinaef orm. Having the form of the genus Sarcina. 
Scabrous. Rough to the touch. 
Sclerotioid. Like a sclerotium. 

Sclerotium. A compact mass of hyphse in dormant state. 
Scopulate. Broom-like or brush-like. 

Scorpioid. With the main axis coiled like the tail of a scorpion. 
Scrupose. Jagged, rough. 
Scutiform. Buckler-shaped. 
Septate. Divided by a partition. 
Septum (a). Any kind of partition. 
Seriate. In a series. 
Sessile. Destitute of a stalk. 
Seta(ae). A bristle or bristle-shaped body. 
Setaceous. Bristle-like. 
Setose, Bristly, beset with bristles. 
Setulose. Resembling a fine bristle. 

Shield-shaped. In the form of a buckler; clypeate, peltate, or scutate. 
Sigmoid. Doubly curved in opposite directions, like the Greek sigma. 
Simple. Of one piece or series, opposed to compound. 
Sinuous. Sinuose. Sinuate. With a deep wavy margin. 
Sorus (i). Heap, or aggregation; a heap of spores. 
Spatulate. Like a druggist's spatula. 
Sperm. A male reproductive cell. 

Spermatum (a). Male non-motile gamete, sometimes erronously used 
for various conidia. 



694 GLOSSARY 

Sphaeroidal. Somewhat spherical. 

Spindleform. Spindle-shaped, fusiform. 

Sporangiophore. A sporophore bearing a sporangium. 

Sporangium. Sac producing spores endogenously. 

Spore. A single cell which becomes free and is capable of developing 

directly into a new plant. 
Sporidium. Diminutive of spore, especially applied to the spores pro- 
duced on promycelia. 
Sporocarp. A many-celled body serving for the formation of spores. 
Sporodochium. The sporiferous apparatus in fungi belonging to 

the Tuberculariales. 
Sporogenous. Producing spores. 

Stellate. Star-shaped or radiating like the points of a star. 
Sterigma (ta) . A stalk-like branch of a basidium bearing a spore. 
Stipe. A general term for stalk. 
Stipitate. Having a stipe. 
Stolon. A sucker or runner. 
Stoloniferous. Bearing stolons. 
Stratose. In distinct layers. 

Striate. Marked with fine longitudinal parallel lines. 
Strigose. With sharp-pointed appressed straight and stiff hairs or 

bristles. 
Stroma (ta). A cushion-like body, on or in which the perithecia are 

immersed. 
Stromatic. Pertaining to or resembling a stroma. 
Stuffed. Solid, farctate. 
Stylospore. A spore borne on a filament. 
Sub. Under or below; in compounds usually implies an approach to the 

condition designated; somewhat or slightly. 
Subiculum. Subicle. A felted or byssoid basal stratum of hyphse. 
Subulate. Awl-shaped. 
Sulcate. Grooved or furrowed. 
Superj&cial. On the surface. 
Suspensor. A club-shaped or conical portion of hypha adjoining a 

gamete-cell. 
Sympodium. An axis made up of the bases of a number of successive 

axes arising as branches in succession one from the other. 
Syn. Signifies adhesion or growing together. 
Synema. A column of combined filaments. 



GLOSSARY 695 



T. D. P. Abbreviation for Thcrmal-death-point. 

Teleutospore. A resting spore of Uridinales on germination producing 

a promycelium. 
Teleuto-stage. Stage producing a teleutospore. 
Telium. A sorus of the Uredinales; see pp. 324-326. 
Terete. Circular in transverse section. 
Ternate. In threes. 

Thalloid. Having the nature or form of a thallus. 

Thallus. A vegetative body without differentiation into stem and leaf. 
Tomentose. Densely pubescent with matted wool, or short hairs. 
Tortuous. Bent or twisted in different directions. 
Torulose. Irregularly bending. Somewhat moniliform with swollen 

portions. 
Tremelliform. Gelatinous in texture. 
Tremelloid. Jelly-like in substance or appearance. 
Trichogyne. The receptive filament of the female organ. 
Trident. Having three teeth. 

Triquetrous. Three-edged, with three salient angles. 
Truncate. As though cut off at the end. 
Tubercular. Having tubercles, or like a tubercle. 
Tuberculate. Beset with knobby projections or excrescences. 
Tubular. Cylindrical and hollow. 
Tumid. Inflated, swollen. 

U 

Umbellate. Having the inflorescence in umbels. 

Umbilicate. Navel-like. 

Umbo. A boss. 

Umbrinaceous. Umbrinous. Umbrinus. Umbrinose. The color of 

raw umber. 
Uncinate. Hooked. 
Ungulate. Having claws or hoofs. 
Unguliform. Hoof-shaped. 
Uni. In composition, one, or single. 
Urceolate. Urceolar. Pitcher-like, hollow and contracted at the mouth 

like an urn. 
Uredinium. A sorus in the Uredinales, see pp. 324-326. 



696 GLOSSARY 



Vacuolate. Possessing vacuoles. 

Valsoid. Resembling Valsa. 

Valvate. Opening by valves. 

Vegetative. Growing. 

Veil. A special envelope in Agaricales within which the growth of the 

sporophore takes place. 
Velutinous. Velvety, due to a coating of fine soft hairs. 
Vermicular. Vermiculate. Worm-shaped, thickened and bent in places. 
Verruciform. Wart-shaped. 

Verrucose. Verrucous. Verruculose. Full of warts. Warty. 
Verticillate. Whorled. 
Vesicular. Composed of vessels. 
Villi. Long weak hairs. 
Villous. Bearing villi. 
Vinose. Vinous. Wine colored. 
Viscid. Sticky from a tenacious coating or secretion. 
Volva. A covering, the sac enclosing the Agaric sporophore. 



Zonate. Marked circularly. 

Zoogloeae. A colony embedded in a gelatinous substance. 
Zoosporangia. Sporangia which produce zoospores. 
Zoospore. A motile spore. 



INDEX 



(Boldface figures refer to headings, italic figures to illustrations) 



Abies, 229, 230, 347, 391, 41G, 

580 
Absidia, 104 
Acacia, 436, 457 
Acanthorhynchus, 224 

Vaccinii, 224, 225 

Acanthostigma, 226, 229 

Parasiticum, 229, 229 

Acer, 188, 202, 499, 507, 529 

Pseudoplatanus, 152, 159 

Aciculosporium, 199 
Acinula, 659 
Acladium, 575 
Acolium, 153 
Aconitum, 93 
Acontium, 571 
Acorus, 73, 320 
Acrasiales, 5 
Acremoniella, 600, 600 

Occulta, 600 

Verrucosa, 600 

Acremonium, 575, 577, 577 
Acrocylindriura, 583 
Acrocystis, 663 

Batata;, 663 

Acrospeira, 599 
Acrospermacese, 160 
Acrostalagmus, 583, 584, 581). 

Albus, 584, 585 

Panax, 585 

Vilmorinii, 585 

Acrotheca, 598 
Acrothecium, 609 
Actidium, 164 



Actiniceps, 634 
Actinida, 181 
558, Actinomma, 656 

Actinonema, 505, 508 

Fagicola, 509 

Fraxani, 509 

Rosffi, 508, 508 

Tilia;, 509 

Actinothecium, 528 

Actinothyrium, 532 

Adonis, 178 

iEcidium, 324, 334, 335, 389, 390 

Abietinum, 349 

Asperifolium, 381 

Berberidis, 334, 378 

Brassica;, 378, 390 

Cinnamomi, 390 

Columnare, 347 

Cyparissise, 372 

Euphorbise-gerardianse, 375 

Grossularise, 376 

Leucospermum, 336 

Mespili, 371 

Otogense, 390 

Oxalidis, 384 

Pelargonii, 390 

Rhamni, 382 

Rubellum, 377 

■ Strobilinum, 347 

Tuberculatum, 390 

iEgerita, 640 

iEsculus, 182, 202, 489, 507, 579 

Agaric, 394 

Agaricacese, 402, 442 

Key to, 442 

Agaricale^, 395, 397 
697 



698 



INDEX 



Agaricales, Key to, 402 
Agaricese, 443, 448 
Agaricus, 448, 455 
Agave, 89, 248, 552 
Agropyron, 306, 320, 389 

Repens, 262 

Agrostis, 321, 380 
Agyriella, 538 
Agyriellopsis, 534 
Albuginaceffi, 78, 82 
Albugo, 78, 79, 82 

Bliti, 79, 81, 82, 102-116 

Candida, 81, 95 

Ipomoese-panduranae, 81 

Occidentalis, 82 

Portulaceae, 82 

Tragopogonis, 82 

Alder, 130, 203, 243, 264, 274, 419, 

428, 545 
Aldridgea, 405 
Aleurodiscus, 404, 405 
Aleyrodes, 194 
Alfalfa, 29, 36, 97, 132, 148, 208, 250, 

258, 315, 408, 486, 508, 514, 521, 

543, 551, 556, 582, 630, 660 
Alfilaria, 71, 101 
Alga-Uke Fungi, 3, 65 
Allantospora, 589 
Allium, 97, 318, 344, 661 
Almond, 36, 357, 498, 542, 626 
Alnus, 186, 188, 278, 408, 541, 582, 

607 
Aloe, 493, 560 
Alternaria, 260, 261, 616, 621 

Brassicse, 621 

Cucurbits, 621 

Dianthii, 622, 622 

Fasciculata, 624 

Fici, 624 

Forsythia;, 621 

Panax, 622 

• Phaseoli, 621 

Solani, 623, 623, 624 

Tabacinum, 624 

Tenuis, 621 

Trichostoma, 262, 621 



Alternaria, Viola;, 621, 621 

Vitis, 624 

Althea, 386 

Alyssum, 178 

Alveolaria, 341 

Amallospora, 657 

Amanita, 398, 450 

Amantiopsis, 450 

Amarantacea;, 303 

Amaranthus, 82 

Amaryllidacea;, 405 

Amblyosporium, 572 

Amelanchier, 183, 366, 368, 369, 370, 

371 
Amentacese, 127 
Amerosporae, 633, 635 

Key to, 636 

Amerosporium, 534 

fficonomicum, 534 

Amoebochytrium, 72 

Ampelopsis, 181, 238, 484 

Amphicarpa, 71 

Amphisphseriacese, 222 

Amphispore, 327 

Anacardiacea;, 127 

Ancylistidiales, 66 

Andromeda, 398 

Anemone, 72, 143, 178, 318, 336, 357, 

389 
Angelinia, 160 
Angiopoma, 515 
Anise, 630 
Anixia, 189 
Annularia, 450 
Antennaria, 190, 192 

Elffiophila, 192 

Footi, 192 

Piniphilum, 192 

Pityophila, 192 

Setosa, 192 

Anthina, 657 
Anthostoma, 277 
Anthostomella, 208, 276 

■ Bohiensis, 277 

Coffea;, 277 

Destruens, 277, 277 



INDEX 



693 



Anthostomella, Sullce, 277 

Anthracoderma, 483 

Anthracophyllum, 445 

Anthrinieai, 594 

Anthurium, 270, 489, 511, 544, 552 

Anthurus, 463 

Antromycopsis, 630 

Aphanoascus, 167 

Aphis, 194 

Apiospora, 251 

Apiosporium, 190, 191, 192 

Brasiliense, 192 

Salicinum, 191, 192 

Aposphseria, 481, 494 

Apple, 36, 38, 52, 88, 105, 122, 123, 
139, 184, 203, 220, 231, 246, 248, 
249, 255, 265, 267, 268, 271, 278, 
285, 329, 365, 367, 368, 371, 404, 
405, 408, 412, 415, 419, 421, 428, 
452, 485, 486, 490, 492, 502, 503, 
504, 515, 519, 539, 540, 542, 546, 
547, 561, 563, 574, 586, 617, 644, 
645, 649 

Rot, 266 

Twig Canker, 266 

Appressoria, 266 

Apricot, 139, 357, 486, 491, 560, 569, 
604, 610 

Aquilegia, 178, 544 

Arachnopeziza, 135 

Aralia, 168 

Arbor Vitae, 424, 431 

Arbutus, 36 

Archangelia, 251 

Armillaria, 123, 450, 455 

Fuscipes, 457 

Mellea, 230, 410, 411, 455, 4S7, 

458 

Mucida, 457 

Arnica, 176 

Aronia, 366, 368 

Arrhenatherum, 180 

Arrhenia, 443 

Arrowroot, 207 

Arthrobotrys, 586 

Arthrobotryum, 637 



Artichoke, 41, 591 
Arundinaria, 211 
Aschcrsonia, 195, 527 
Asciculosporium Take, 211 
Asclepias, 188 
AscobolacesB, 133, 134 
Ascochyta, 243, 409, 505, 506 

iEsculi, 507 

Aquilegia;, 507 

Armoraciffi, 506 

Aspidistra?, 507 

Beticola, 507 

Boltshauseri, 506 

Brassicaj, 506 

Caulicola, 508 

Chrysanthemi, 507 

Cookei, 508 

Corticola, 508 

Digitalis, 507 

Dianthi, 507 

Ellisii, 506 

Fragaria;, 507 

Graminicola, 508 

Imperfecta, 508 

Iridis, 507 

Juglandis, 507 

Lactuca;, 507 

Lycopersici, 508 

Manihotes, 508 

Medicaginis, 507 

Melutispora, 508 

Nicotiana;, 506 

Orobi, 507 

Pallida, 507 

Parasitica, 506 

Piniperda, 507 

Pisi, 506 

Polemonii, 507 

■ Populicola, 507 

Primulse, 507 

Pruni, 507 

Rhei, 506 

Tremula;, 508 

Vicise, 503 

Viola;, 507 

AscocorticiaceiB, 125 



700 



INDEX 



Ascoideaceae, 118 
Ascomycetes, 64, 113 

Key to, 117 

Ascospora, 235, 236 

Beijerinckii, 236, 560 

Geographicum, 237 

— ^— Himantia, 236 

Padi, 237 

Aseroe, 463 

Ash, 52, 164, 203, 232, 255, 284, 419, 
421, 433, 509, 524, 530, 557, 564, 
603, 608 
Asparagus, 41, 328, 376, 553, 617, 

630, 660 
Aspedistra, 507, 552 
Aspen, 255, 428, 446, 607 
Aspergillaccaj, 165, 166 

Key to, 166 

Aspergillales, 114, 124, 164, 167 

Key to, 165 

Aspergillea;, 566, 572, 572 

Key to, 572 

AspergiUus, 166, 167, 168, 169, 572, 
573 

Ficuum, 169, 572 

Fumigatus, 572 

Phocnicis, 169, 572 

Aster, 89, 179, 289, 328, 585, 654 
Asterocystis, 68, 69 

Radicis, 69 

Asterodon, 413 
Asteroma, 274, 482, 496 

Codiaji, 496 

Geographicum, 496 

Padi, 275, 496 

Punctiforme, 496 

Stuhlmanni, 496 

Asterophora, 577 
Asterosporium, 558 
Asterostomella, 481, 531 
Asterostomidium, 514 
Asterostroma, 406 
Asterothyrium, 531 
Astragalus, 187 
Astrodochilum, 655 
Atractiella, 634 



Atractina, 609 
Atractium, 207 
Atriplex, 74 
Atrocarpus, 273, 541 
Attachment organs, 141, 142 
Auerswaldia, 216 
Aulographum, 163 
Aureobasidium, 403, 405 

Vitis, 405 

Auricula, 611 
Auricularia, 393 

Auricula judia3, 393 

Auriculariacea;, 392 

Key to, 392 

Auriculariales, 323, 326, 392 

Key to, 392 

Auriculariese, 393 
Auta^cious, 329 
Avena, 608 
Avocado, 512 
Azalea, 523 



B 



Bacillus, 18, 21, 37 

Ampelopsorse, 51, 37 

Amylovorus, 3S, 38 

Anthracis, 37 

Apii, 39 

Araliavonis, 39 

Aroidea;, 39, 39, 42 

Atrosepticus, 40, 47 

Avena?, 24, 40, 40 

Beta;, 41 

Brassicsevorus, 27, 41 

Caratovorus, 39, 40, 41, 42, 46 

Caulivorus, 27, 43 

Cepivorus, 43 

CoU, 43 

Cubonianus, 31, 43 

Cypripedii, 43 

• Dahlia;, 43 

Delphini, 43 

Elegans, 43 

Glanga3, 52 



INDEX 



701 



Bacillus, Gossyj)ini, 43 

Gum mis, 43 

Haria, 44 

Hyacinthi Septicus, 39, 44 

Inflatus, 15 

Koraiensis, 39 

Lactuca?, 44 

Lycopersici, 44 

Maculicola, 44 

Megatherium, 13, 15 

Melangenus, 44 

Melonis, 44, 44, 4-5 

Mori, 21 

Mycoides, 45 

Nicotianse, 45 

Olea;, 45 

Oleracea;, 39, 42, 46 

Omnivorus, 42, 46 

Oncidii, 46 

Oryzse, 46 

Pestis, 37 

Phytophthorus, 46 

Populi, 47 

Prodigiosus, 21 

Pseudarabinus, 47 

Rosarum, 47 

Sacchari, 52 

Sesami, 47 

Solanacearam, 30, 45, 47, 49 

Solanicola, 48 

■ Solaniperda, 48 

Solanisaprus, 47, 48, 48, 49 

Sorghi, 49 

Spongiosus, 49 

Subtilis, 15, 49 

Tabacivonis, 50 

Tabificans, 50 

• Tracheiphilus, 50, oO, 57 

Typhosus, 19, 37 

Uva;, 37, 51 

Vulgatus, 51 

Zea^, 51 

Zinzgiberi, 52 

Bacteria, 1, 3, 13, 18 

• Cell structure, 14 

Classification, 17 



Bacteria, Constancy of species, 17 

Entrance to the host plant, 

17 

Group numbers, 20 

Involution forms, 16 

Migula, system of, 18 

Mode of increase, 14 

Modes of spore germination, 16 

Numerical system of recording, 

19 

Specific characters, 19 

Spores, 15 

Three type forms, 13 

Bacteriacese, 18, 21 
Bacterium, 18, 21 

Briosianum, 21 

Fici, 22 

Montemartinii, 21 

Pini, 22 

Scabigenum, 22 

Teutlium, 22 

Tuberculosis, 19 

Bactridiopsis, 640 
Bactridium, 645 
Bseodromus, 341 
Bagnisiella, 216 
Bahamia, 11 
Balansia, 199, 209, 209, 537 

Claviceps, 209 

Hypoxylon, 209 

Balsam, 423, 436 

Bamboo, 209, 211, 215, 310 

Banana, 52, 214, 253, 448, 496, 540, 

542, 608, 626, 649, 650 
Barberry, 333, 380, 385, 546 
Barclay ella, 341 

Bariey, 24, 105, 180, 206, 249, 260, 
261, 304, 305, 306, 307, 315, 333, 
380, 383, 550, 567, 587, 601, 613, 
621 
BartaHnia, 513 
Barya, 198 
Basiascum, 553 
Basidiella, 636 
Basidiobolacese, 107 
Key to, 107 



702 



INDEX 



Basidiobolus, 107 
Basidiomycetes, 64, 298, 475 

Key to, 299 

Basidiophora, 83, 89 

Entospora, 89 

Basisporium, 599 

Baumanniella, 411, 412 

Bean, 12, 31, 37, 86, 267, 373, 408, 

487, 491, 506, 540, 548, 621, 630, 637 
Beccariella, 406 
Beech, 106, 134, 152, 162, 203, 249, 

415, 421, 427, 429, 430, 433, 436, 

440, 444, 445, 509, 544, 545, 547, 

608 
Beet, 8, 22, 26, 36, 37, 41, 44, 45, 50, 

52, 73, 82, 100, 187, 247, 258, 321, 

412, 486, 490, 507, 526, 568, 590, 

610, 617, 620, 628, 645, 660 
Begonia, 43, 168, 544 
Belanioscypha, 136 
Belonidium, 147 
Beloniella, 147 
Belonium, 136 
Belonopsis, 147 
Beltrania, 602 
Beniowskia, 639 
Berberis, 185, 188, 235, 256, 329, 379, 

384 
Berlesiella, 283 
Bertia, 226 
Beta, 374 
Betula, 130, 157, 186, 188, 202, 220, 

221, 255, 348 
Betulaceae, 143 
Bibliography of introduction, Myxo- 

mycetes and Bacteria, 53 

Ascomycetes, 288 

Books, 678 

Basidiomycetes, 466 

Fungi Imperfecti, 667 

Periodicals, 680 

Phycomycetes, 109 

Biologic species and specialization, 

174, 260, 262, 332, 380, 611, 640 
Birch, 418, 421, 426, 428, 430, 433, 

436, 444, 446, 545, 607 



Bird nest fungi, 395 
Bispora, 601 
Bizzozeria, 234 
Bizzozeriella, 640 
Blackberry, 276, 360, 525 
Black-leg, 652 
Blastomyces, 575 
Blastotrichum, 200, 588 
Blennoria, 538 
Bletia, 552, 645 
Blossoms, 107, 108 
Bloxamia, 538 

Blue grass, 213, 385, 497, 550 
Blue-green Algse, 3 
Boletacese, 402, 440 

Key to, 440 

Boletinese, 440 
Bolinia, 285 
Bombardia, 226 
Bombardiastrum, 227 
Bonia, 406 
Bonplandiella, 655 
Boraginacese, 329, 382 
Borago, 178 
Bornetina, 323 
Bostrichonema, 586 
Botryodiplodia, 510, 513 
Botryospha;ria, 283, 2S3, 503 

Dothidffi, 284 

Gregaria, 284 

Ribis, 283 

Botryosporium, 571 

Diffusum, 571 

Longibrachiatum, 571 

Pulchrum, 571 

Botrytidea;, 566, 574, 575 

Key to, 575 

Botrytis, 86, 91, 96, 137, 142, 570, 578 

Cinerea, 140, 578, 578, 581 

Citricola, 581 

Deprsedens, 580 

Diospyri, 581 

Douglasii, 141, 581 

Fascicularis, 580 

Galanthina, 141, 581 

Infestans, 681 



INDEX 



703 



Eotrytis, Longibrachiata, 581 

Pajoniae, 580 

Parasitica, 580 

Patula, 581 

Vulgaris, 140 

Boudiera, 115, 116 

Bovilla, 224 

Bovista, 465 

Bovistella, 465 

Box, Buxus, 204, 220, 221, 243, 529, 

656 
Box elder, 545 
Brachysporium, 609 
Brachy-type, 328 
Brassica, 69, 178, 390, 617, 629 
Bread fruit, 411 
Brefeldiacca;, 10 
Bremia, 84, 90, 95 

Lactucae, 95, 95 

Briarea, 572 
Briosia, 636 
Bromus, 260, 261, 613 
Broomella, 199 
Brown alga;, 3 
Brunchorstia, 532 

Destruens, 151, 532 

Bubakia, 340 

Buckwheat, 378, 589, 607, 660 

Bulb, 141, 661 

Bulgaria, 151, 152 

■ Polymorpha, 152 

Bulgariea;, 151 

Bulgariella, 151 

BuUaria, 556 

Burillia, 315 

Buseella, 570 

Butomus, 323 

Butternut, 275, 419, 428, 545 

Byssocystis, 482 



Cabbage, 7, 24, 25, 26, 29, 41, 42, 46, 
52, 69, 73, 81, 95, 231, 249, 378, 
408, 484, 491, 492, 530, 544, 619, 
503, 654 

Cacao, 130, 204, 205, 206, 232, 277, 



278, 409, 411, 448, 4-93, 509, 512, 

525, 536, 552, 553, 573, 584, 585, 

590, 592, 620 
Cacospha>ria, 281 
Cactus, 36, 488, 512, 544 
Ca;oma, 334, 335, 342, 358, 361, 389, 

390 

Nitens, 360 

Orchidis, 344 

Pinitorquum, 344 

Calamagrostis, 661 
Calcarisporium, 583 
Calceolaria, 52 
Calendula, 176, 178, 321 
Caliciacese, 134, 163 

Key to, 153 

Calicium, 153 
Calistephenis, 338 
Calla, 39, 488, 560, 631 
Calloriea;, 147 
Calocasia, 89 
Calonectria, 198, 205 

Bahiensis, 206 

Cremea, 205, 585 

Flavida, 205 

Gigaspora, 206 

Platani, 205 

Pyrochroa, 205, 648 

Calospha;ria, 281, 282 

Princeps, 282, 282 

Calosphariese, 281 
Calospora, 280, 539 

Vanilla;, 280, 541 

Calyptromyces, 104 
Camarops, 285 
Camarosporium, 516, 517, 617 

Fissum, 517 

Mori, 517 

Viticola, 617 

Camellia, 497, 559, 561 
Campanella, 443 
Campanula, 101, 333, 340 
Camphor, 411 
Camposporium, 609 
Campsotrichum, 599 
Camptosphaeria, 263 



704 



INDEX 



Camptoum, 598 
Canker, 266, 349 
Canna, 389 
Canteloupe, 620 
Cantharelleffi, 442, 443 

Key to, 443 

Cantharellus, 443 
Caper, 81, 630 
Capillaria, 659 
Capnodiastrum, 501 
Capnodium, 190, 192, 624 

Citri, 193 

Citricolum, 193 

Coffea;, 192 

Foedum, 192 

GuajaviB, 192 

Javanicum, 193 

Meridionale, 193 

Olea, 193 

Quercinum, 192 

Stellatum, 193 

Taxi, 192 

Tilia;, 192 

Capparis, 179 
Capronia, 252 
Capsule, 14 
Caragana, 524, 525 
Caravonica, 411 
CarduaceiE, 303 
Carex, 303, 376 

Carnation, 27, 52, 375, 408, 497, 523, 
544, 553, 578, 580, 581, 611, 623, 
645, 654 
Carpinus, 130, 188, 191, 492, 545 
Carrinia, 504 
Carrot, 27, 41, 42, 44, 91, 119, 141, 

142, 260, 408, 491 
Carya, 186, 202, 546 
Caryophyllaceaj, 310, 405 
Cassava, 493, 543 
Castanea, 140, 186, 188, 558, 562 
Castilloa, 411 
Castor plant, 89, 654 
Casuarina, 571 

Catalpa, 168, 178, 18G, 188, 256, 426, 
489, 619 



Catastoma, 465 
Catenularia, 600 
Catinula, 534 

Cattleya, 253, 273, 541, 544 

Caudospora, 277 

Cauliflower, 25, 26, 28, 46, 95, 
544 

Caulocassia, 100 

Cedar, 234 

incense, 424 

Celastrus, 188 

Celery, 27, 39, 41, 42, 52, 377, 487, 
492, 521, 619, 628 

Celidiaceai, 134 

Cenangella, 150 

Cenangiacese, 134, 150 

Key to, 150 

Cenangium, 150, 151, 152 

Abietis, 151, 532 

Vitesia, 500 

Centaurea, 178, 377 

Cephaliophora, 588 

Cephalodochium, 641 

Cephalosporiea}, 566, 570 

Key to, 570 

Cephalosporium, 201, 571, 646, 649 

Cephalotheca, 166 
Cephalothecium, 586 

Roseum, 586, 5S6 

Cephalotrichum, 598 
Ceraplastes, 194 
Ceratiomyxaceae, 9 
Coratocarpia, 190 
Ceratocladium, 630 
Ceratophorum, 608, 610 

Setosum, 610 

Ulmicolum, 610 

Ceratosphseria, 232 
Ceratostoma, 232 
Ceratostomatacese, 222, 232 

Key to, 232 

Ceratostomella, 232 

Pilifera, 233, 233 

Cercis, 5t)6, 524 

Cercospora, 243, 257, 478, 625 

Acerina, 632 



INDEX 



705 



Corcosponi, Acerosum, 630 

Altha^ina, 630 

Angreci, 631 

Angulata, 245, 626 

Apii, 628, l!2S 

Arimincnsis, 630 

Armoraciae, 629 

Asparagi, 630 

Beticola, 628, 628 

Bloxami, 629 

Bolleana, 626 

Brunkii, 631 

Capparidis, 630 

Cerasella, 245, 625 

Cercidicola, 631 

Cheiranthi, 631 

Circumscissa, 625 

Citrullina, 629 

Concors, 626, 626 

Cruenta, 629 

Cucurbitaj, 629 

Flagelliformis, 629 

Fumosa, 626 

Gossypina, 248, 625 

Halstedii, 632 

Hypophylla, 631 

• Kellermanii, 630 

Kopkei, 630 

Longipes, 630 

-. Malkoffi, 630 

Malvarum, 630 

Medicaginis, 630 

Melonis, 629 

Microsora, 631 

Moricola, 626 

Miisa;, 626 

Neriella, 631 

Nicotianaj, 627, 627 

Odontoglossi, 631 

Omphacodes, 631 

Oryzse, 626 

Personata, 629 

Phlogina, 631 

Raciborskii, 627 

Resedse, 631 

Richardiaecola, 631 



Ceroospora, Roesleri, 626 

Rosicola, 630, 630 

Rubi, 626 

Sacchari, 630 

Sequoia?, 632 

Sordida, 631 

Theaj, 630 

Unicolor, 631 

Vagina;, 630 

Vigna;, 630 

Violaj, 630 

Viticola, 626 

Cercosporelki, 592 

Albo-maculans, 592 

Inconspicuus, 592 

Narcissi, 592 

Pastinacffi, 592 

Persies;, 592 

Cereal, 248, 250, 385, 491, 600 

Cereus, 499, 529 

Cerocorticium, 405 

Cerotelium, 341 

Cesatiella, 198 

Ceuthospora, 483, 500 

Cattleya, 500, 500 

Coffeicola, 500 

Chaenotheca, 153 
Chsetocladiaceae, 103 
Chsetoconidium, 577 
Chffitodiplodia, 510 

VaniUae, 510 

Chaetomella, 501 
ChBetomiaceae, 222 
Chffitopeltis, 532 
Chaetophoma, 191, 482, 495 

Glumarum, 495 

Chsetospermum, 641 
Chaetosphaeria, 226 
Chffitostroma, 201, 655, 666 

Buxi, 656 

Cliviae, 656 

Chsetozythia, 527 
Chalara paradoxa, 596 
Chalarieae, 595 
Chamaecyparis, 370, 416 
Characese, 3 



706 



INDEX 



Charrinia, 262, 263 
Cheiranthus, 619, 631 
Chenopodiaceae, 96 
Chenopodium, 74 

Cherry, 49, 129, 138, 184, 219, 237, 
245, 255, 268, 275, 282, 357, 376, 

419, 507, 512, 520, 560, 562, 604, 
606, 625, 649 

Cherry laurel, 410 

Chess, 550 

Chestnut, 36, 101, 209, 281, 321, 419, 

420, 439, 442, 445, 489, 498, 499, 
509, 524, 560, 597 

Chicory, 490 
China berry, 202 
Chitonia, 448 
Chitonospora, 251 
Chlamydobacteriacese, 19 
Chlamydospores, 60 
Chlorophycea?, 3 
Chlorosplenium, 135, 144 

iEruginosum, 143, 144 

Choanephora, 107 

Americana, 107 

Cucurbitarum, 107 

Infundibulifera, 107 

Choanephoracese, 103, 106, 107 
Chondromyces, 634 
Chromosporium, 566 
Chrysanthemum, 36, 105, 386, 389, 

392, 409, 488, 492, 507, 522, 563, 

569 
Chrysomyxa, 341, 350 

Abietis, 350 

Chrysophlyctis Endobiotica, 70, 71 
Chrysopsora, 336 
Chytridiales, 60, 65, 66, 101 

Key to, 67 

Ciboria, 135 
Cicer, 179 

Cichorlum, 178, 378 
Cicinnobella, 501 
Cicinnobolus, 174, 482, 494 
Cienkowskia, 11 
Ciliciopodium, 634 
Ciliofusarium, 657 



Ciliospora, 527 

Cineraria, 339 

Cinnamon, 390, 398, 487 

Cintractia, 302, 310 

Cionothrix, 342 

Circinella, 105 

Cissis, 303 

Citron, Citrus Fruits, 44, 45, 193, 

194, 249, 490, 491, 504, 512, 520, 

540, 541, 548, 559, 574, 581, 604, 

605, 626, 649 
Citysus, 100 
Cladobotyrum, 583 
Cladochytriacese, 67, 72 

Key to, 72 

Cladochytrium, 72 

Brassicse, 73 

Csespitus, 73 

Graminis, 73 

Mori, 73 

Tenue, 73 

Viola?, 73 

Viticolunj, 73 

Cladoderris, 406 

Cladosphseria, 283 

Cladosporium, 217, 219, 257, 602, 

603, 617 

Bigarardia, 605 

Brunneo-atrum, 606 

Carpophilum, 604, 60^ 

Citri, 604 " 

Condylonema, 605 

Cucumerinum, 603, 604 

Elegans, 604 

Epiphyllum, 606 

Fasciculare, 260, 603 

Fulvum, 604, 605 

Graminum, 605 

Herbarum, 248, 603 

Citricolum, 604 

Hypophyllum, 606 

Javanicum, 606 

Juglandis, 606 

Macrocarpum, 605 

Orchidis, 605 

Oryzae, 605 



INDEX 



707 



Cladosporium, Oxycocci, 606 

Pconiae, 600 

Pisi, 605 

Scabies, 606 

Scribnerianum, 606 

Sicophilum, 604 

Tuberum, 606 

Zeai, 606 

Cladosterigma, 634 
Cladotrichum, 601 
Clanostachys theobromse, 206 
Clasterosporium, 60S, 609 

Amygdalearum, 610 

Carpophilum, 500, 610 

Glomerulosum, 610 

Putrefaciens, 610 

Clathracese, 462, 463 

Key to, 463 

Clathrus, 464 
Claudopus, 449 
Clautriavia, 462 
Clavaria, 412 
Clavariacete, 402, 412 

Key to, 412 

Claviceps, 199, 211, 211, 213, 215, 643 

Microcephala, 213 

Paspali, 213 

Purpurea, 212, 643 

Rolfsii, 213 

ClavicipitejE, 196, 197 
— Key to, 199 
Cleistotheca, 190 
.Clematis, 43, 178, 179, 390, 492, 544, 

563 
Clinoconidium, 640 
Clithris, 156, 157, 157 

Aureus, 157 

Juniperus, 157 

— — - Quercina, 157 
Clitocybe, 450, 457, 459, 569 

Parasitica, 458 

Clitopilus, 450 
Clivia, 656 
Clonostachys, 584 
Clostridium Butyricum, 13 
Persicae tuberculosis, 63 



Clove, 415 

Clover, 71, 74, 97, 143, 187, 206, 220, 
221, 258, 373, 374, 494, 543, 551, 
569, 582, 593, 606, 619, 630 

Clusia, 560 

Clypeosphajria, 276 

Clypeospha?riacea\ 223, 276 

Key to, 276 

Coccaceaj, 18, 21 

Cocci, 13 

Coccomyces, 156, 563 

Cocconia, 156 

Coccophacidium, 156 

C'occospora, 566 

Coccosporella, 566 

Coccosporium, 616 

Cocoa, 88 

Cocoanut, 43, 191, 193, 433, 512, 
513 

Codiaeum, 496, 544 

Coemansia, 583 

Coemansiella, 571 

Coffee, 168, 170, 192, 193, 195, 205, 
207, 249, 250, 277, 356, 409, 415, 
486, 500, 504, 512, 515, 525, 543, 
553, 583, 591, 597, 635, 643, 660 

Colchicum, 375, 563 

Coleosporiacea?, 335 

Key to, 336 

Coleosporium, 326, 333, 336, 390, 391 

Campanula", 339 

Ipomoeae, 337 

Pini, 339 

Senecionis, 338, 338 

Solidaginis, 337, 337 

Coleroa, 226, 227, C58 

Chsetomium, 227, 227 

Sacchari, 227 

Collacystis, 527 

Collard, 25, 95, 619 

CoUetotrichum, 147, 264, 267, 268, 
538, 539, 540, 547 

• Agaves, 552 

Altha;ae, 552 

Ampelinum, 549 

Anthurii, 662 



708 



INDEX 



CoIIetotrichum, Antirrhini, 553 

Bletise, 552 

Brachytrichum, 553 

Camellia?, 553 

Carica, 549, oJ^O 

Cereale, 550, noO 

Cincta, 269, 547 

Coffeanum, 553 

Cradwickii, 553 

Cyclamena', 553 

Dracsenae, 553 

Elasticse, 552 

Falcatum, 549 

Gloeosporioides, 549 

Gossypii, 267, 272, 547 

Hedericola, 553 

Hevese, 553 

Incarnatum, 553 

Kentise, 552 

Lagenarium, 548 

Lineola, 550 

Lindemuthianum, 267, 543, 547, 

Luxificum, 552 

Macrosporum, 553 

Malvarum, 552 

Nigrum, 551 

Oligochffitum, 548 

Omnivorum, 552 

— ^ Phomoides, 551 

Piperitum, 551 

PoUaccii, 553 

Primulse, 552 

Rubicolum, 270, 5^7 

Schizanthi, 552 

Spinaciaj, 551 

Theobroma;, 553 

Theobromicolum, 553 

Trifolii, 551 

Violse-tricoloris, 552 

cGollodochium, 640 
CoUonema, 517 
Collybia, 450, 458 

Velutipes, 458, ^60 

Columbine, 507 
Colus, 464 



Colutea, 187 

Completoria, 107 

Complens, 108 

Composite, 82, 92, 95, 178, 386 

Comptonia, 352 

Conidiobolus, 107 

Conifers, 132, 145, 159, 161, 162, 203, 
229, 235, 350, 390, 417, 418, 423, 
431, 436, 452, 512, 547, 559, 579, 
654 

Coniocybe, 153 

Pallida, 153 

Coniophora, 405 

ConiosporieEe, 594, 595 

Key to, 595 

Coniosporium, 595, 595 

Filicinum, 595 

Onobrychidis, 595 

Coniothecium, 615 

Chomatosporum, 617 

Coniothyrium, 245, 257, 501, 503 

Anomale, 504 

Brevisporum, 504 

Coffea;, 504 

Concentricum, 503 

Diplodiella, 263, 504, 604 

Fuckelii, 257, 258, 503 

Hellebori, 505 

Japonicum, 504 

Megalospora, 228 

Melastorum, 503 

Pyriana, 503 

Scabrum, 504 

Tumefaciens, 503 

Vagabundum, 504 

Wernsdorffiaj, 505 

Conjugate, 3 

Conjugate division, 321, 331, 332 

Convallaria, 494 

Convolvulacese, 82 

Coprinese, 442 

Corallodendron, 633 

Corallomyces, 199 

Cordana, 602 

Cordieritidacese, 134 

Cordyceps, 199 



INDEX 



709 



Coremium, 230, G34, 635, 635 

Coreopsis, 176 

Corethropsis, 571 

Coronella, 570 

Corn, 34, 52, 90, 101, 308, 310, 312, 

329, 408, 511, 512, 606, 613, 614, 

650 
Cornularia, 517 
Cornus, 188, 191, 279, 524 
Coronophora, 281 
Corpyha, 560 
Corticium, 403, 405, 406, 409 

■ Chrysanthemi, 409 

Comedens, 409 

Dendriticum, 409 

Javanicum, 409 

La;tum, 408 

Lilacino-fuscum, 409 

Vagum-solani, 404, J^06, 407, 

660 

Zimmermannii, 409 

Cortinarius, 449 

Corydalis, 344 

Corylus, 188, 408, 530, 545, 557 

Corymbomyces, 583, 584, 584 

Albus, 205, 584 

Coryneliacese, 222 
Corynespora, 629 
Corynetes, 131 
Coryneum, 558, 560, 564, 658 

Beijerinckii, 236, 237, 560, 561 

Camellise, 561 

Folliicolum, 561 

Juniperinum, 560, 658 

Modonia, 560 

Mori, 561 

Cosmonectria, 201 

Cosmos, 493 

Costinellus, 450 

Cotton, 29, 36, 43, 249, 267, 272, 303, 

361, 408, 411, 486, 492, 547, 589, 

619, 625, 650, 651 
Cotton-wood, 437 
Cotoneaster, 366 
Couturea, 515 
Cowpea, 187, 487. 521, 535, 651 



Cranberry, 71, 140, 225, 231, 267, 277, 
397, 486, 495, 500, 520, 525, 529, 
536, 543, 559, 606, 614 
Crandallia, 532 
Crataegus, 130, 183, 188, 255, 366, 

367, 368, 569 
Craterellus, 406 
Craterium, 12 
Creonectrieaj, 196 
Cribrariaceae, 9 
Crocicreas, 481 
Crocus, 121, 143 
Cronartium, 341, 350, 351, 390, 391 

Asclepiadeum, 352 

Comptoniae, 352, 352 

Quercus, 352, 390 

Ribicola, 350 

Crotalaria, 408 

Crotonocarpia, 226 

Crown gall, 12 

Crucifer, 6, 25, 41, 43, 69, 81, 95, 616, 

619, 621 
Crumenula, 150 
Cryptocoryncum, 608 
Crjqjtodcris, 263 
Cryptomela, 553 
Cryptomyces, 156, 158 

Maximus, 158 

Cryptospora, 279 
Cryptosporella, 279, 280 

Anomala, 280 

Viticola, 280, 282, 498 

Cryptosporiuni, 562, 564 

Leptostromiforme, 564 

Minimum, 564 

Cryptostictis, 515, 516, 516 

Caudata, 516 

Cynosbati, 516 

Cucumber, 44, 45, 46, 51, 52, 76, 95, 

141, 247, 404, 487, 543, 548, 569, 

604, 606, 608, 615, 617, 629, 

652 
Cucumis, 178 
Cucurb, 6, 51, 94, 95, 107, 178, 179, 

487, 509, 521, 539, 548, 651 
Cucurbita, 178 



710 



INDEX 



Cucurbitaria, 234 

Berberdis, 235, 235 

Elongata, 235 

Laburni, 235 

Picese, 235 

Pityophila, 235 

■ Sorbi, 235 

Cucurbitariaceaj, 222, 234 

Key to, 234 

Cudoniese, 131 

Cuphea, 187 

Cupressus, 369 

Currant, 92, 148, 155, 203, 207, 284, 

351, 433, 499, 500, 519, 542, 626 
Curry a, 216 
Curryella, 216 
Cuttings, 644 
Cyanocephalium, 198 
CyanophyceEe, 3 
Cyanospora, 232, 233 

Albicedra;, 233, 283 

Cyathicula, 136 
Cycad, 248, 516 
Cyclamen, 52, 168, 268, 488, 492, 522, 

553 579 
Cycloconium, 601, 602, 603 

Oleaginum, 603 

Cyclomyces, 417 
Cyclostomella, 163 
Cydonia, 366, 368 
Cylindrium, 568 
Cylindrocephalum, 571 
Cylindrocladium, 586 
Cylindrocolla, 641 
Cylindrodendrum, 577 
Cylindrophora, 576 
Cylindrosporium, 243, 562, 662 

Castanicolum, 249, 562 

Cercosporoides, 564 

Chrysanthemi, 563 

Clematidis, 563 

Jackmani, 563 

Colchici, 563 

Humuli, 563 

Inconspicuum, 563 

Mori, 249, 525, 562 



Cylindrosporium, Orni, 564 

Padi, 562, 562, 563 

Pomi, 563, 563 

Quercus, 564 

Saccharinum, 563 

Tubeufianum, 563 

Viridis, 564 

Cylindrotrichum, 575 

Cymbridium, 547 

Cynachum, 352 

Cynodon, 221 

CyperaceaJ, 303 

Cyperus, 89, 303, 408 

Cyphella, 406 

Cystophora, 598 

Cytisus, 235, 253, 375, 610 

Cytodiplospora, 505 

Cytoplea, 501 

Cytospora, 209, 279, 483, 499, 499 

Acerina, 499 

— — Ceratophora, 499 

Palmarum, 499 

Rubescens, 278 

• Sacchari, 499 

Cytosporella, 483, 498 

Cerei, 499 

Citri, 499 

Damnosa, 499 

Persicse, 499 

Cytosporina, 518, 526, 526 

Ribis, 526 

Cytosporium, 516 
Cystothyrium, 531 
Cystotricha, 505 
Cyttariacese, 134 

D 

Dacromycetales, 395, 396 
Dacryodochium, 641 
Dacrymycella, 640 
Dactylaria, 588 
Dactylella, 588 
Dactylium, 588 
Dactylopias, 194 
Dactylosporium, 616 



INDEX 



711 



Dadap, 411 
Daedalea, 417, 439 

Quercina, 439, UO 

Dahlia, 43, 178, 492, 645 
Daisy, 36 
Daldinia, 285 
Dammara, 489 
Damping Off, 77 
Dandelion, 71, 119, 378, 590 
Daphne, 544 
Darluca, 335, 505 
Darwinella, 216 
Dasyscypha, 135, 144, /44 

Abietis, 145 

Calyciforniis, 145 

Resinaria, 145 

Subtilissima, 145 

Willkommii, /44, 145 

Date, 169, 310 
Datura, 48 
Daucus, 178 
Deconica, 449 
Delacourea, 252 
Delitschia, 224 
Delphinium, 178, 321 
Dematiacese, 565, 594 

Key to, 594 

AmerosporiE, 594, 599 

Key to, 599 

Dictyosporse, 594, 615 

Key to, 615 

Didymospora;, 599, 601 

Key to, 601 

Heliocosporse, 594 

Phragmosporse, 594, 608 

Key to, 608 

Saturosporse, 594 

Scolecosporse, 594, 625 

Key to, 625 

Dematium, 217, 600 

Prunastri, 495 

Dematophora, 230 

Glomerata, 201 

Necatrix, 230, 2S1 

Dendrodochium, 640, 643 
Lycopersici, 643 



Dendrographium, 637 
Dcndrophagus Globosus, 12 
Dendrophoma, 481, 494, J^9l^ 

Convallaria', 494 

Marconii, 494 

Valsispora, 494 

Dendrostilbella, 633 
Dendryphieai, 609, 615 
Dendryphium, 615 

Cornosum, 615 

Dermatea, 151, 152, 152 

Acerina, 152 

Carpinea, 152 

Cinnamomea, 162 

Prunastri, 152 

Dermateaj, 150 
Dcsmazierella, 135 
Desmodium, 187, 188 
Dewberry, 648 
Diachnai, 11 
Diachora, 216, 217 

Onobrychidis, 217 

Dialonectria, 201, 205 

Dianthus, 101, 312, 328, 375, 387, 

488, 507, 619, 654 
Diaphanium, 639 
Diaporthe, 277, 278, 279, 490, 498 

Albocarnis, 279 

Ambigua, 279, 490 

Parasitica, 209 

Sarmentella, 279, 490 

Strumella, 279, 499 

Taleola, 279 

Diatomese, 3 
Diatrypaceaj, 223, 281 

Key to, 281 

Diatrypea;, 281 
DichsenacejE, 160, 162 
Dichea, 162 

Faginea, 162 

Quercina, 162, 16S 

Dicheirinia, 353 
Dichlsena, 527 
Dichomera, 516 
Dicoccum, 601, 602 
Rosae, 602 



712 



INDEX 



Dicotyledones, 203 
Dictyophora, 462, 463 
Dictyosporse, 633 
Dictyosporium, 615 
Dictyuchus, 75 

Monosporus, 75 

Dicyma, 598 
Di derma, 10 

Didymaria, 586, 587, 587 
Didymella, 251, 255, 256 

Citri, 256 

Didymiacese, 10 

Key to, 10 

Didymium, 9, 10 

Daedalium, 10 

Didymochseta, 505 
Didymocladium, 586 
Didymopsis, 586 
Didymopsora, 342 
Didymosphseria, 251, 25f>, 256 

Catalpa;, 256 

Epidermidis, 256 

Populina, 256 

Spheroides, 256 

Didymosporse, 633 
Didymosporium, 556, 556 

Salicinum, 556 

Dieback, 278 

Diervilla, 178 

Dietelia, 342 

Digitalis, 100, 488, 507 

Digitaria, 591 

Dill, 377 

Dilophia, 251, 257, 525, 590 

Graminis, 256, 257, 525 

Dilophospora, 518, 525, 525 

Graminis, 257, 525 

Dimargaris, 572 
Dimerosporium, 189, 191 

CoIIinsii, 191 

Mangiferum, 191 

Pulchrum, 191, ir,'l, 625 

Dinemasporium, 534, 535, 535 

Oryzae, 535 

Dinoflagellates, 3 
Diospyrus, 183 



Diplocladium, 200, 586, 653 
Diplococcium, 602, 603 

Conjunctum, 603 

Diplodia, 243, 510, 511, 511, 
513 

Aurantii, 512 

Cacaoicola, 512 

Cerasorum, 512 

Citricola, 512 

Coffeicola, 512 

Destruens, 512 

Epicocos, 512 

Gongrogena, 512 

Heteroclita, 512 

Macrospora, 511 

Mori, 512 

Natalensis, 512 

Opuntise, 612 

Oryzeaj, 512 

Perseana, 512 

Pinea, 512 

Rapax, 512 

Sapinea, 512 

Zea;, 511 

Diplodiella, 510, 512, 512 

Oryzae, 512 

Diplodina, 247, 505, 509, 509 

Castanese, 509, 509 

Citrullina, 247, 509 

Corticola, 509 

Parasitica, 509 

Salicina, 509 

Diplodiopsis, 510 
Diplophysa, 73 
Diplorhinotrichum, 585 
Diplosporium, 586 
Dipsacus, 176, 178 
Discella, 536, 536 

Cacaoicola, 536 

Discocyphella, 406 
Discomycetes, 116, 117, 123, 159 
Discomycopsella, 531 
Discomycopsis, 501 
Discosia, 531 

Pini, 531 

Discula, 534, 535, 535 



511, 



INDEX 



713 



Discula, Platani, 274, 535 
Dispira, 572 
Ditopella, 263, 264 

Ditopa, 264 

Fusispora, 264 

Doassansia, 301, 315, 322, 322 

Gossypii, 323 

NiessUi, 322 

Dogwood, 158, 203 
Dolichos, 373 
Doratomyces, 571 
Doscocolla, 645 
Dothichiza, 534, 535, 535 

Ferruginosa, 152 

Populea, 535 

Dothidiaceae, 215 

Key to, 216 

DothichlcE, 210 

Aristida), 210 

Atramentosa, 210 

Dothidea, 216, 218, 220 
Noxia, 220 

Rosa;, 220 

Dothidella, 219, 221 

Betulina, 221 

Thoracella, 221 

Ulmi, 221 

Dothidiacese, 215 

Key to, 216 

Dothidiales, 124, 195, 215 

Dothiochloe, 199 

Dothiopsis, 483 

Dothiora, 155, 156 

Virgultorum, 157 

Dothiorella, 284, 483, 499 

Mori, 499, 499 

Populi, 499 

Ribis, 499 

Dothiorellina, 483, 499 

Tankoffii, 499 

Double Blossom, 648 

Downy Mildew, 82 

Dracsna, 270, 487, 489, 497, 503, 
553 

Dracaenacea;, 303 

Drepanospora, 609 



Drupe, 139, 236, 237, 410, 486 
Durio, 221 
Dusiella, 211 
Dyctilium, 200 



E 



Earlea spiciosum, 359 
Eccilia, 450 
Echinobotryeae, 594 
Echinodontium, 414, 415 

Tinctorium, 415 

Echinodorus, 315 
Echinodothis, 199, 211 

Tuberiformis, 211 

Ectostroma, 657 

Ectrogella, 68 

Egg plant, 37, 42, 47, 204, 268, 408, 

487, 491, 508, 539, 540, 580, 617 
Elaphomycetacese, 165 
Elder, 185, 393 
Eleutheromyces, 197 
Elm, 71, 127, 130, 182, 221, 249, 260, 
393, 421, 430, 437, 455, 484, 489, 
503, 530, 544, 557, 608 
Emericella, 167 
Emmer, 206, 550 
Enchnoa, 262 
Endive, 377 

Endobotrya, 516 

Endoconidium, 146, 639, 641, 641 

Temulentum, 642 

Endogone, 118 

Endomyces, 122 

Decipiens, 123 

Mali, 122, 123, 123 

Parasitica, 123 

Endomycetacese, 120, 122, 165 

Key to, 122 

Endophyllum, 342, 353 

Sempervivi, 353 

Endothia, 283 

Entoloma, 450 

Entomogenous fungi, 194 

Entomophthoraceae, 107 



714 



INDEX 



Entomophthorales, 66, 102, 107 

Key to, 107 

Entomosporium, 243, 531, 532, 532 

Maculatum, 149, 532 

Mespili, 150, 532 

Thumenii, 632 

Entyloma, 314, 320 

Australe, 322 

Betiphilum, 321 

Calendulse, 321 

Crastophilum, 321 

Ellisii, 321, 321 

Fuscum, 322 

Irregulare, 321 

Lephroideum, 321 

Polysporum, 321 

Enzymes, 2 
Ephelis, 209, 537 
Epichloe, 199, 210, 210, 211 

Typhina, 210, 643 

Epicoccum, 655, 656, 656 

Hyolopes, 656 

Epidochiopsis, 641 
Epidochium, 655, 656 

Oryzse, 656 

Epilobium, 347 

Epochnium, 601 

Eremascus, 122 

Ergot, 213 

Erica, 617 

EricaceiB, 143, 159, 186, 397 

Erigeron, 89 

Erinella, 136 

Eriobotrys, 607 

Eriocaulacea), 303 

Eriopeziza, 135 

Eriospora, 518 

Eriosporangium, 355 

Eriosporina, 515 

Eriothyrium, 528 

Erysiphaceai, 117, 166, 170, 171, 176, 

192 

Key to, 174 

Erysiphales, 332, 475, 494, 569 
Erysiphe, 117, 143, 166, 172, 173, 

175, 177 



Erysiphe, Cichoracearum, 174, 178, 
178, 569 

Graminis, 171, 179, 179, 569 

Liriodendri, 178 

Martii, 178 

Polygoni, 177, 177, 178, 187 

Taurica, 179 

Umbelliferarum, 178 

Erysiphea, 260 
Euascomycetes, 117, 123 

Key to, 123 

Eubacteriales, 18 
Eubasidii, 299 
Eubasidiomycetes, 394 

Key to, 394 

Eucalyptus, 310, 560 
Eumycetes, 1, 3, 59 

Key to, 64 

Eunectria, 201, 202 

Euphorbia, 187, 329, 330, 372, 374, 

375 
Eurotiopsis, 167, 527 
Eusclerotinia, 137 
Eutaphrina, 127 
Eutypa, 278 
Eu-type, 328 
Excipula, 534 
Excipulacese, 479, 533 

Key to, 533 

Hyalodidyma;, 533, 537 

Key to, 536 

Hyalophragmiae, 533, 536 

Hyalosporae, 533 

Key to, 534 

Phseophragmiae, 533, 536 

Phseospora;, 533 

Scolecospora?, 533, 536 

Key to, 536 

Excipularia, 657 
Exoascacese, 125 

Key to, 126 

Exoascales, 396 
Exoascus, 125, 127 
Exobasidiales, 125, 395, 396 

Key to, 396 

Exobasidium, 396 



INDEX 



715 



Exobasidium, Andromedse, 396, 397 

Azalese, 398 

Cinnamomi, 398 

Japonicum, 398 

Lauri, 398 

Oxycocci, 397 

Peckii, 398 

Rhododendri, 398 

Vaccinii, 397 

Vexans, 397 

Vitis, 398 

Exosporina, 656, 656 

Laricis, 656 

Exosporium, 227, 657, 658 

Juniperinum, 560, 658 

Laricinum, 658 

Palmivorum, 658, 658 

Preslii, 658 

Rubinus, 227 

Tiliai, 658 



Fabacese, 303 
Fabrsa, 147, 243 

Malculata, 149, 149, 532 

Mespili, 150, 532 

Fagopyrum, 178 
Fagus, 188, 545 
Farlowiella, 160 
Favolus, 417, 439 

Australis, 438 

Europa^us, 43S, 439 

Fenestrella, 278 

Ferments, organic, 2 

Fern, 77, 108, 126, 250, 581, 595 

Festuca, 180, 310, 383, 635 

Ficaria, 375 

Ficus, 205, 249, 267, 278, 533, 544, 

552 
Fig, 22, 169, 310, 346, 408, 549, 564, 

572, 573, 604, 624, 626, 643 
Filbert, 280 
Fimbrystylis, 303 
Fir, 132, 145, 162, 192, 203, 276, 

320, 347, 349, 418, 424, 431, 434, 



438, 440, 465, 490, 492, 493, 507, 

568, 581, 657 
Fission, 14 
Fistulina, 440, 441 

Hepatica, 441, 442 

Fistulinea;, 440 
Flagella, 14 
Flammula, 449, 452 

Alnicola, 452 

Penetrans, 452 

Spumosa, 452 

Flax, 69, 343, 653 
Floccomutinus, 462 
Fodder, 599 
Fomes, 417, 418, 663 

Annosus, 431 

Applanatus, 433, 436 

Australis, 437 

Carneus, 430 

Everhartii, 430 

Fomentarius, 426, 429, 429 

Fraxinophilus, 433 

Fulvus, 433 

Fulvus olesc, 433 

Hartigii, 434 

Igniarius, 401, 428, 428, 429, 433, 

434 

Juniperinus, 431 

Laricis, 432 

Lucidus, 433 

Marmoratus, 434 

Nigricans, 433 

Pinicola, 435, 436 

Ribis, 432 

Robiniae, 434 

Semitosus, 437 

Sessilis, 435 

Ulmarius, 437 

Forget-me-not, 101 
Form Genera, 476 
Forsythia, 621 
Fox Tail, 90 
Fracchia?a, 234 
Fragaria, 176, 244 
Fraxinus, 188 
Fruits, 106 



716 



INDEX 



Fuckelia, 152, 155, 483, 500 

Ribis, 500 

Fuligo, 11, 12, 200 

Fumago, 191, 616, 624 

Camellia;, 194, 625 

Fungi, 1, 3 

Classification, 64 

Imperfecti, 64, 475 

Key to, 479 

Slime. See Mycomycetes. 

True, 1, 2, 59 

Funkia, 489 

Fusariella, 608 

Fusarium, 201, 204, 203, 475, 571, 
645, 646 

Acuminatum, 652 

iEruginosum, 652 

Affine, 652 

Aurantiacum, 651 

■ Avenaceum, 206 

Blasticola, 654 

Brassica?, 654 

Cocruleum, 647, 648, 652 

Commutatum, 648, 652 

Cubense, 649 

Cucurbitariae, 652 

Culmorum, 206, 649, 6^9 

Decemcellulare, 654 

Dianthi, 654 

Didymium, 647, 652 

Diplosporum, 652 

Discolor, 648 

Sulphureum, 648 

Erubescens, 653 

— — Falcatum, 648 

Gemmiperda, 649 

Gibbosum, 648 

Heterosporum, 206 

— Hordei, 206 

Incarnatum, 654 

Limonis, 649 

Lini, 653, 653 

Lycopersici, 653 

Martii, 648 

Metachroum, 648 

Moniliforme, 650 



Fusarium, Nivale, 205 

Niveum, 651 

Oxysporum, 648, 651, 652, 653 

Pelargonii, 654 

Pestis, 652 

Pini, 654 

Platani, 205, 648 

Putrefaciens, 649 

Rhizogenum, 649 

Ricini, 654 

Roseolum, 652 

Roseum-lupini-alba, 652 

Rubi, 648 

Rubiginosum, 647, 648 

Solani, 204, 585, 648, 652 

Subulatum, 648 

Tabacivorum, 654 

Theobromse, 648, 654 

ITdum, 651 

Vasinfectum, 205, 650, 650, 651 

Pisi, 648, 651 

Tracheiphila, 651 

Violaceum, 652 

Violae, 654 

Wilkommii, 648 

Fusella, 595 
Fusicladium, 253, 602, 606 

Betula?, 255, 607 

Cerasi, 255, 606 

Dendriticum, 253, 255, 607 

Depressum, 607 

Destruens, 607 

Effusum, 607 

Eriobotryse, 607 

Fagopyri, 607 

Fraxini, 255, 606 

Lini, 607 

Orbiculatum, 255, 607 

Pirinum, 253, 607 

Saliciperdum, 606 

Tremulse, 255, 607 

Vanilla;, 607 

Fusicoccum, 274, 280, 483, 498 

Amygdali, 498 

Bulgarium, 498 

Perniciosum, 281, 498 



INDEX 



717 



Fusicoccum, Veronense, 275, 498 

Viticolum, 498, 498 

Fusicolla, 639 

Fusidium, 201, 203, 5G7, 568 

Candidum, 568 

Fusisporium solani, 648 
Fusoma, 588, 590 
Parasiticum, 590 



G 



Galera, 449 
Gallowaya, 339 
Gamospora, 517 
Gamosporclla, 483 
Gaphiothecium, 630 
Garden-pea, 408 
Garlic, 97 

Gasteromycetes, 395 
Gaylussacia, 397 
Geaster, 465 
Gelatinosporium, 518 
Geminispora, 263 
Gemmae, 60 
Gentiana, 352, 389 
Geoglossacese, 131, 154 

Key to, 131 

Geoglosseaj, 131 
Geoglossum, 131 
Geotrichum, 568 
Geranium, 52, 315, 390, 591, 603, 631, 

654 
Gherkin, 247 
Gibbellina, 251, 256 

Cerealis, 256 

Gibellula, 634 
Gibbera, 234 
— Vaccinii, 234, 235 
Gibberella, 198, 206, 646 

Cerealis, 207 

Moricola, 207 

Saubineitii, 206, 206 

Gibberidea, 234 
Gibelia, 283 
Ginger, 77 



Ginkgo, 267 

Ginseng, 39, 88, 141, 496, 559, 585, 

622, 651 
Giulia, 532 

Gladiolus, 250, 318, 320, 389 
Gleditschia, 2G7 
Glenospora, 599 
Gliobotrys, 570 
Gliocephalus, 570 
Gliocladium, 574 

Agaricinum, 574 

Gliodcladium, 572, 574 

Globaria, 465 

Gla^ocephala, 412 

Gloeoporus, 417 

Gloeosphajra, 583 

Gloeosporium, 147, 252, 264, 266, 267, 

269, 274, 475, 478, 538, 539, 547 

Affine, 544 

Alborubrum, 544 

Allescheri, 545 

Alneum, 545 i 

Ampelophagum, 541 

Amygdalinum, 542 

Anthuriophilum, 544 

Apocryptum, 545 

Aquiligise, 544 

Atrocarpi, 273, 541 

Begonise, 544 

Berberidis, 546 

Betularum, 545 

Betulinum, 545 

Beyrodtii, 544 

Bicolor, 541 

Bidgoodii, 544 

Bruneum, 544 

Cactorum, 544 

Canadense, 546 

Carpini, 545 

Caryae, 545 

Cattleya;, 544 

Caulivorum, 543 

Cinctum, 541 

Cingulatum, 268, 541 

Citri, 541 

Clematidis, 544 



718 



INDEX 



Gloeosporium, Coffeanum, 543 

Concentricum, 544 

Coryli, 545 

Crotonis, 544 

Curvatum, 542 

Cydonise, 542 

Cylindrospermum, 541 

Cytisi, 544 

Depressum, 541 

Dianthi, 544 

Diospyri, 542 

Elastica;, 267, 544 

Euphobiae, 544 

Fagi, 545 

Fagicolum, 544 

— — Fragaria", 542 

Fructigenum, 267, 539 

Helicis, 544 

Hendersonii, 541 

Inconspicuum, 544 

Intermedium, 541 

Juglandis, 545 

Kawakami, 546 

Laeliae, 544 

Laeticolor, 267, 539 

Lagenarium, 543 

Macropus, 253, 541 

Malicorticis, 493, 542, 5Jt2 

Mangiferse, 543 

Manihotis, 543 

Medicaginis, 543 

Melengonea, 539 

Mezerei, 544 

— Minus, 543 

Morianum, 543 

Musarum, 542 

Importatum, 542 

Myrtilli, 543 

Nanoti, 546 

Nervicolum, 545 

Nervisequum, 274, 541 

Olivarum, 543 

OpuntiiE, 544 

Pallidum, 544 

Paradoxicum, 157, 541 

Pelargonii, 544 



Gloeosporium, Pestis, 643 

Piperatum, 269, 541 

Platani, 274 

Psidii, 271, 541 

Quercinum, 545 

Rhododendri, 544 

Ribis, 148, 541 

Rosae, 544 

Rufomaculans, 265, 235, 267, 

539 

Saccharini, 545 

Salicis, 148, 541 

Soraurianum, 544 

Spegazzinii, 541 

Stanhopeicola, 544 

Tamarindi, 546 

Thea, 544 

Sinensis, 544 

Tiliaceum, 545 

Tilia;, 545 

Tremulse, 545 

Trifolii, 543 

Umbrinellum, 544 

VanilliE, 280, 541 

Variabile, 542 

Venetum, 542 

Versicolor, 267, 539 

Violse, 544 

Gloesporiella, 555 

Glomerella, 263, 264, 475, 539, 547 

Atrocarpi, 273, 541 

Cactorum, 265 

Cincta, 269, 270, 541, 547 

Cingulata, 268, 541 

Gossypii, 267, 271, 272, 273, 

547 

Piperata, 269, 270, 271, 541 

Psidii, 270, 541 

Rubicolor, 270, 547 

Rufomaculans, 264, 265, 266, 

267, 268, 269, 270, 271, 272, 539, 

541, 548 

Cyclaminis, 268 

Glomerularia, 566 
Gloniella, 161 
Glonium, 163 



INDEX 



719 



Clumaceae, 199 

Glutinium, 481, 630 

Glyceria, 383 

Glycophila, 567 

Glycyrrhiza, 187 

Gnomonia, 264, 274, 529, 539 

Carya;, 545 

Erythrostoma, 275 

Leptostyla, 275, 555 

Oryza;, 276 

Padicola, 275, 496 

Quercus lUicis, 275 

Rubi, 276 

Veneta, 274, 274, 275, 498, 

535, 541, 546 

Gnomoniaceai, 223, 263 

Key to, 263 

Gnomoniella, 283, 273, 539 

Coryli, 274 

Fimbriata, 274 

Tubiformis, 274, 274, 529, 

541 

Gnomoniopsis, 264, 265 

Godroniella, 534 

Golden Rod, 179 

GonatobotrytidiEe, 566 

Gongromeriza, 596 

Gooseberry, 141, 148, 155, 185, 245, 
351, 433, 504, 519, 526 

Gordonia, 150 

Gorgonicepes, 136 

Gossypium, 168 

Gourd, 95, 247 

Grain, 257, 260, 333, 384, 451, 508, 
599, 620 

Grallardia, 176, 178 

Gramineae, 143, 179 

Grandinia, 413 

Granularia, 640 

Grape, 36, 37, 43, 51, 52, 73, 141, 148, 
153, 192, 201, 231, 242, 249, 250, 
253, 258, 267, 268, 281, 345, 398, 
405, 463, 484, 486, 490, 491, 494, 
498, 504, 506, 517, 520, 540, 541, 
549, 554, 560, 579, 580, 620, 
626 



Graphiola, 323, 663 

Phoenicis, 664, 665 

Graphiothecium, 243 

Graphium, 630 

Grass, 8, 11, 24, 69, 73, 209, 210, 

211, 213, 220, 259, 260, 303, 

310, 312, 320, 321, 329, 333, 379, 

383, 385, 405, 508, 520, 612, 635, 

661 
Green Algae, 3 
Grossulariae, 493 
Guava, 271, 541 
Guelichia, 641 
Guignardia, 236, 237, 484 

Ampelicida, 238 

Baccaj, 242 

Bidwellii, 238, 238, 239, 241, 

484, 490 

Buxi, 243 

Thea;, 243 

Vaccinii, 242, 242 

Gymnoascacese, 165 
Gymnoascus, 164 
Gymnoconia, 355, 359, 390 

Interstitialis, 360, 360 

Gymnosporangium, 330, 355, 361, 

362, 391 

Biseptatum, 370 

Clavariseforme, 331, 363, 365, 

366 

Clavipes, 363, 368 

Cornutum, 368, 371 

Ellisii, 369 

Germinale, 368 

Globosum, 363, 366 

Japonicum, 371 

Juniperinum, 367 

Juniperi-virginianae, 329, 363, 

364 

Nelsoni, 363, 370 

Nidus-avis, 363, 369 

Sabinse, 369 

Terminali-juniperinum, 371 

Transformans, 369 

Yamada?, 371 

Gyroceras, 596 



720 



INDEX 



H 



Hackberry, 93 
Hadrotrichum, 600 
Haematomyces, 151 
Hsematomyxa, 151 
Hainesia, 538 
Halobyssus, 567 
Hamamelis, 188 
Haplaria, 575 
Haplariopsis, 586 
Haplobasidium, 597 
Haplographiese, 595, 600 

Key to, 6l)0 

Haplographium, 601 
Haplosporella, 501 
Haplotrichum, 571 
Hariotia, 163 
Harknessia, 501 
Harpocephalum, 630 
Harpographium, 630 
Hartigiella, 570, 575 

Laricis, 570 

Hartigielleai, 566, 570 

Hawthorn, 38, 39, 130, 502, 525 

Hazel, 122, 203, 249, 274, 280, 444 

Hebeloma, 449 

Hedera, 249, 487, 522, 541, 553 

Helianthus, 92, 178, 179, 388 

Helicobasidium, 403 

Heliomyccs, 445 

Heliscus, 645 

Hellebore, 505 

Helminthospora, 609 

Helminthosporium, 260, 584. 609, 611 

Avenai, 613 

Bromi, 261, 613 

Gramineum, 261, 612, 612, 614 

Hevea;, 614 

Iberidis, 614 

Inaequalis, 614, 614 

Inconspicuum, 613, 614 

Lunaria^, 614 

Oryza>, 614 

Sativum, 613, 613 

Sigmoideum, 613 



Helminthosporium, Sorokinianum, 
613 

Teres, 612, 613 

Theaj, 614 

Trichostoma, 612 

Tritici, 613 

Tritici Repentis, 262, 613 

Turcicum, 613, 614 

Vaccinii, 234 

Helostroma, 634 
Helotiacea), 133, 134 

Key to, 135 

Helotieae, 136 
Helotium, 136 
Helvellaceae, 131 
Helvellales, 123, 130 

Key to, 131 

Hemiascomycetes, 114, 117, 118 
Hemibasidii, 298, 299 
Hemiglossum, 131 
Hemileia, 354, 355 

Oncidii, 356 

Vastatrix, 355, 355 

Woodii, 356 

Hemi-parasites, 2 

Hemi-saprophytes, 2 

Hemi-type, 328 

Hemlock, 418, 419, 423, 435, 436, 438 

Hemp, 52, 101, 141, 486, 494, 521, 581 

Hendersonia, 257, 264, 516, 615 

Acicola, 515 

Coffeaj, 516 

CydoniE, 516 

Foliicola, 516 

Mali, 515 

Notha, 516 

Oryzae, 516 

Piricola, 515 

Togniniana, 515, 516 

Hendersonula, 515, 516 

Morbosa, 219 

Henriquesia, 160 
Hepatica, 93, 357 
Heptameria, 252 
Heracleum, 591 
Hericiura, 413 



INDEX 



721 



Herpotrichia, 226, 229, 230 

Nigra, 229 

Heterobotrys, 595 
Heterocephalum, 634 
Heterocontse, 3 
Hetercecism, 64, 329 
Heteropatella, 534 
Heterosphffiria, 155 
Heterosporium, 609, 610 

Auriculi, 611 

Echinulatum, 611 

Gracile, 611 

Laricis, 611 

Minutulum, 611 

Ornithogali, 611 

Syringa;, 611 

Variabile, 611 

Heterotheca, 408 

Heuchera, 188 

Hevea, 207, 278, 287, 411, 418, 437, 

513, 544, 553, 607 
Hexagonia, 417 
Heydenia, 630 
Hiatula, 450 
Hibiscus, 488 
Hickory, 428 
Hicoria, 396 
Himantia, 657 
Holchus, 383 
Hollyhock, 328, 38G, 487, 492, 523, 

552, 630 
HolstieUa, 280 
Holwaya, 151 
Homostegia, 216 
Honey dew, 190 
Honeysuckle, 36, 191 
Hop, 8, 36, 93, 175, 279, 486, 490, 

5G3, 569,590,611 
Hordeum, 180, 317, 379 
Hormiactella, 601 
Hormiactis, 586 
Hormiscium, 596 
Hormodendrum, 600, 601 

Cladosporioides, 248 

Hordei, 601, 601 

Hornbeam, 152, 274 



Horse Chestnut, 445, 460, 524 
Horse Radish, 95, 96, 506, 522, 582, 

590, 619, 629 
Hoya, 544 
Humulus, 176, 178 
Hyacinth, 27, 42, 44, 75, 143, 231, 

260, 603 
Hyaloceras, 558 
Hyalodema, 593 
Hyaloderma, ICO 
Hyalodothis, 217 
Hyalopus, 570 
Hyalospora, 341 
Hydnacea?, 402, 413 

Key to, 413 

Hydnocha^te, 414 
Hydnum, 414, 414 

Diversidens, 415 

Erinaceus, 414, 414 

Schiedermayeri, 415 

Septentrionale, 414 

Hydrangea, 347, 488, 493, 522 
Hygrophorese, 442 
Hymenium, 113 
Hymenocha;t£E, 406 

Noxia, 411 

Hymenogast rales, 396 
Hymenomycetes, 394 
Hymenopsis, 655 
Hymenoscypha, 136, 146, 146 

Temulenta, 146, 642 

Hymenula, 640 
Hypha, 657 
Hyphaene, 193 
Hyphoderma, 575 
Hypholoma, 449, 450 

Appendiculatum, 451, 4^1 

Fasciculare, 451 

Lateritium, 451 

Hyphomycete, 321, 402, 663 
Hyphostereum, 640 
Hypocenia, 501 
HypochnacejE, 402 

Key to, 403 

Hypochnus, 403, 406 
Cucumeris, 404 



722 



INDEX 



Hypochnus, Filamintosus, 404 

Fuciformis, 404 

Ochroleucus, 403 

Solani, 404 

These, 404 

Hypochytriacese, 67 
Hypocopra, 224 
Hypocrea, 209, 199 

Ceretiformis, 209 

Sacchari, 209 

Hypocreaceae, 196 

Key to, 196 

Hypocreales, 124, 195, 584 
Hypocreeaj, 197 

Key to, 198 

Ilypocrella, 199 
Hypocreodendron, 527 
Hypocreopsis, 199 
Ilypoderma, 161 

Desmazieri, 161 

Laricis, 161 

■ Pinicola, 161 

Strobicola, 161 

Hypodermatacea;, 160 

Key to, 160 

Hypodermella, 160, 161 

Laricis, 161 

Sulicigena, 161 

Hypodermium, 538, 547 

Orchidearum, 547 

Hypolyssus, 405 

Hypomyces,, 197, 200, 200 

Hyacinthi, 200 

Solani, 200 

Hypomycetese, 196, 197 

Hyponectria, 201 

Hyponectriese, 196 

Hypospila, 276 

Hypoxylea;, 285 

Hypoxylon, 285 

Hysteriacese, 160, 163, 530 

Key to, 163 

Hysteriales, 124, 159 

Key to, 160 

Hysteriopsis, 161 

Brasiliensis, 161 



Hysterium, 164 
Hysteroglonium, 163 
Hysterographium, 164 

Fraxini, 164, 164 

Hysterostomella, 163 



Iberis, 614 
Ilex, 188 
Illosporium, 641, 643 

Maculicola, 644, 6^ 

Malifoliorum, 643 

Impatiens, 93, 176 

Inocybe, 449 

Ipomese, 337 

Iris, 27, 41, 46, 73, 389, 507, 514, 522, 

608, 611, 619, 620 
Irish Potato, 105, 106 
Irpex, 414, 415 

Destruens, 415 

Flavus, 415, U5 

Fusco-violaceus, 415 

Paradoxus, 415 

Isaria, 196, 634, 635 

Fuciformis, 635 

Graminiperda, 635 

Isariopsis, 637, 638 

Griseola, 637 

Isothea, 276 

Itajahya, 462 

Ivy, 152, 493, 497, 544 



Jansia, 462 

Johnson Grass, 311 

Juglans, 186, 275, 396, 507 

Juncus, 303 

Juneberry, 38 

June Grass, 578 

Juniper, 52, 157, 162, 220, 230, 243, 

330, 560 
Juniperus, 362, 365, 366, 367, 368, 

369, 370, 371, 516, 610 



INDEX 



723 



K 

Kalmusia, 277 
Kawakamia, 83, 89 

Cyperi, 89 

Keithia, 156 
Kellermania, 513 
Klachbrennera, 464 
Kmetia, 640 
Kneiffiella, 413 
Kuehneola, 355, 361 

Gossypii, 361 

Uredinis, 361 



Laboulbeniales, 124 
Labrella, 529, 530 

Coryli, 529, 530 

Piricola, 530 

Laburnum, 544 
Lachnella, 135, 145, 145 

Pini, 145 

Lachnellula, 135 
Lachnocladium, 412 
Lachnodochium, 641 
Lachnum, 136 
Lactariea?, 423, 443 
Lsestadia, 238 

Buxi, 243 

Lamyella, 483 

Langloisula, 576 

Larch, 145, 161, 162, 249, 348, 419, 

424, 432, 436, 438, 530, 570, 611, 

656, 658 
Larix, 230, 344 
Larkspur, 43 
Laschia, 417 
Lasiobotrys, 189, 191 

Lonicera?, 191 

Lasioderma, 634 
Lasiodiplodia, 510, 613 

Thoobroma;, 513 

Tubericola, 513 

Lasionectria, 201 



Lasiosphaeria, 226 
Lasmenia, 531 
Laternea, 463, 464 

Columnata, 464, 464 

Lathyrus, 217, 313, 372 

Laurel, 492 

Laurel, Cherry, 409 

Laurus, 398, 489 

Lecythium, 198 

Legume, 28, 31, 32, 313, 373 

Lemalis, 521, 534 

Lembosia, 163 

Lemon, 77, 494, 508, 510, 512, 518, 

540, 549, 574, 582, 604 
Lemonniera, 593 
Lentinus, 445 

Conchatus, 446 

Lepideus, 446, 446 

Variegata, 446 

Lentomita, 232 
Lenzites, 417, 439 

Abietina, 440 

Betulina, 440, 44I 

Corrugata, 440 

Sepiaria, 440 

Variegata, 440 

Vialis, 440 

Leocarpus, 11 

Lepiderma, 10 

Lepidonectria, 201 

Lepotia, 450 

Leptoglossum, 443 

Leptomitaceae, 75 

Leptonia, 450 

Leptopus, 443 

Leptospha?ria, 252, 257, 519, 660 

Circinans, 258 

Coniothyrium, 257, 258, 504 

Ilerpotrichoides, 258 

Iwamotoi, 258 

Napi, 258, 616 

Phlogis, 258, 519 

Rhododendri, 258 

Sacchari, 258 

Stictoides, 258 

Taxicola, 259 



724 



INDEX 



Leptosphseria, Tritici, 258, 520 

Vagabunda, 259 

Vitigena, 258 

Leptospora, 226 
Leptostroma, 529, 530 

Larcinum, 249, 530 

Piricola, 530 

Punctiforme, 530 

Leptostromatacea;, 479, 528 

Key to, 528 

HyalodydimfE, 528 

Hyalosporse, 528 

Key to, 528 

Hyalophragmiffi, 528, 531 

Key to, 531 

Phaeodidymse, 528 

Phseopharagmise, 528 

Phseosporae, 528, 531 

Key to, 531 

Scolecosporaj, 528, 532 

Key to, 532 

Leptostromella, 532, 533 

Elastics, 533, 533 

Leptothyrium, 274, 528, 529 

Acerinum, 529 

Alneum, 274, 529 

Buxi, 529 

Macrothecium, 529 

Oxycocci, 529, 529 

Parasiticum, 529 

Peonse, 529 

Periclymeni, 529 

Pomi, 529 

Lepto-type, 328 

Lespedeza, 187 

Lettuce, 36, 37, 44, 52, 95, 141, 142, 

408, 507, 522, 555, 556, 579, 620 
Levieuxia, 501 
Levisticum, 28 
Libertella, 562, 564 

Rubra, 208, 564 

Ulcerata, 564 

Libertiella, 527 
Liceacea?, 9 
Lichenopsis, 515 
Lichens, 134 



Lilac, 88, 404, 488, 581, 582, 611 

LiliaceiB, 310, 318, 320 

Lilium, 375 

Lily, 106, 141, 250, 488, 563, 579, 580, 

592, 631 
Lily-of-the-valley, 523, 581 
Limacinia, 190 

Tangensis, 193 

Lime, 203, 249 

Limnanthemum, 315 

Linaria, 168 

Linden, 259, 421, 545, 560 

Linospora, 276 

Linum, 667 

Liriodendron, 188, 258, 547 

Lisea, 197 

Lisiella, 197 

Listeromyces, 657 

Lizonia, 226 

Lobelia, 492 

Locellina, 449 

Loculistroma, 199, 215 

Bambusaj, 215 

Locust, 419, 434 
Locust Black, 438 
Lolium, 73, 383 
Lonicera, 186, 191, 529 
Lopharia, 413 
Lophiostomatacese, 223 
Lophium, 164 
Lophodermium, 161 

Abietis, 162 

Brachysporum, 162 

Gilvum, 162 

Juniperinum, 162 

Laricinum, 162 

Macrosporum, 162, 162 

Nervisequum, 162 

Pinastri, 161, 162 

Loquot, 553 
Lunaria, 614 
Lupine, 560, 564, 652 
Lupinus, 43, 178, 313 

Albus, 168 

Augustifolius, 168 

Luteus, 168 



INDEX 



725 



Lupinus, Thermis, 168 
Luzula, 303 
Lycoperdaceae, 464 

Key to, 464 

Lycoperdales, 395, 464 
Lycoperdon, 465 

Gemmatum, 465, 46'5 

Lycopersicum, 178 
Lysurus, 463 



M 



Macrodendrophoma Salicicola, 253, 

494 
Macrobatis, 514 
Macrodiplodia, 510 
Macrophoma, 284, 481, 493 

Abietis, 493 

Curvispora, 493, 4S5 

Dalmatica, 493 

Helicinia, 493 

Hennebergii, 493 

Ligustica, 493 

Malorum, 493 

Manihotis, 493 

Reniformis, 494 

Taxi, 493 

Vestita, 493 

Macrosporium, 616, 618 

Aductum, 619 

Alliorum, 618 

Brassies, 619 

Catalpae, 619 

Cheiranthi, 619 

Cladosporioides, 620 

Commune, 260, 618 

Cucumerinum, 619, 620 

Faseiculata, 624 

Gramineum, 620 

Herculeum, 618 

Iridis, 619 

Longipes, 619 

Lycopersici, 624 

Macalpinianum, 620 

Nigricanthium, 619 



Macrosporium, Nobile, 619 

Porri, 618 

Ramulosum, 619 

Rugosa, 624 

Saponaria;, 620 

Sarciniforme, 619 

Sarcinula-parasitieum, 618 

Tabacinum, 619 

Tomato, 624 

Uvarum, 620 

Verrucosum, 620 

Viola", 620 

Macrostilbum, 634 

Madia, 92 

Magnolia, 188, 503, 559 

Magnusia, 166 

Magnusiella, 126 

Maguey, 220 

Mahonia, 379 

Malbranchea, 567 

Mal-di-gomma, 649 

Malope, 386 

Malus, 371 

Malva, 386 

Malvaceaj, 507 

Mamiania, 263 

Mandarin, 520 

Mangel, 41, 645 

Mango, 191, 193, 543 

Mangold, 491, 581 

Manihot, 557 

Maple, 72, 130, 152, 159, 182, 203, 
419, 421, 428, 430, 436, 455, 489, 
524, 525, 545, 557, 563, 632 

Marasmiese, 443, 445 

Key to, 445 

Marasmius, 445, 446 

Equicrinus, 448 

Ilawiiensis, 448 

Plicatus, 447, 448 

Sacchari, 448 

Sarmentosus, 448 

Semiustus, 448 

Marchalia, 156 ' 

Marchaliella, 189 

Marssonia, 147, 274, 556 



726 



INDEX 



Marssonia, Castagnei, 157, 555 

Juglandis, 275, 555 

Martini, 555 

Medicaginis, 556 

Panattoniana, 555 

Perforans, 555 

Populi, 555 

Potent ilia;, 555 

Rosa?, 555 

Secalis, 555 

Violaj, 556, 556 

Martensella, 576 
Martindalia, 633 
Massalongiella, 236 
Massaria, 263 

Theicola, 263 

Massariaceaj, 223, 262 

Key to, 2G2 

Massarina, 263 
Massariovalsa, 263 
Massospora, 566 
Mastigosporium, 588, 590 
Mastomyces, 155, 514 

Friesii, 514 

Matrouchotia, 403 
Mattirolia, 198 
Mazzantia, 216 
Medicago, 178 
Medick, 148 
Medlar, 140, 150, 569 
Megalonectria, 198 
Melanconiales, 479, 527 
Melampsora, 340, 342, 390 

Allii-fragilis, 344 

AUii-populina, 344 

Allii-salicis albae, 344 

Bigelowii, 344 

Klebahni, 344 

Larici-pentandrse, 344 

Larici-populina, 344 

Lini, 342 

Medusae, 343 

Pinitorqua, 344 

Repentis, 344 

Ribesii-viminalis, 344 

Rostrupii, 344 



Melampsora, Saxifragarum, 345 
Melampsoraceae, 335, 340 

Key to, 340 

Melampsorella, 341, 348, 390, 391 

Elatina, 348 

Melampsoridium, 341, 347, 3^7, 391 

Betula;, 348 

Melampsoropsis, 341, 349, 350, 391 

Rhododendri, 349 

Melanconiacese, 537 

Key to, 537 

Hyalodidymse, 538, 555 

Key to, 555 

Hyalophragmiaj, 538, 556 

Key to, 556 

Hyalosporse, 538 

Key to, 538 

Phseodictyffi, 537, 561 

Phajodidyma;, 537, 556 

Key to, 556 

Phseophragmise, 537, 557 

Key to, 557 

Phaeospora;, 537, 553 

Key to, 553 

Scolecosporse, 537, 561 

Key to, 562 

Staurosporse, 537 

Melanconiales, 265, 525, 537, 564 
Melanconidacese, 223, 279 

Key to, 279 

Melanconiella, 279 
Melanconiopsis, 501 
Melanconis, 279, 281 

Modonia, 281, 498, 560 

Melanconium, 553, 554 

Fuligineum, 554, 554 

Pandani, 554 

Sacchari, 554 

Melanomma, 227, 232 

Cdumarum, 232 

Henriquesianum, 231 

Melanops, 283, 284, 503 
Melanopsamma, 227 
Melanopsichium, 302 
Melanospora, 196, 197, 200, 201 
Damnosa, 200 



INDEX 



727 



Melanospora, Stysanophora, 201 
Melanosporea?, 196, 197 
Melanostroma, 538 
Melanotacnium, 314 
Melasmia, 158, 529, E30 

Acerina, 159, 530 

Punctata, 530 

Salicina, 530 

Melica, 497 

Melilotus, 508 

Aleliola, 189, 190, 191, 193, 193, 624 

Camellia^, 193, 193, 625 

Niesslcanea, 194 

Penzigi, 194 

Melogramma, 283 

Henriquetii, 284 

Melogrammatacese, 223, 282 

Key to, 283 

Melon, 10, 27, 487, 608, 621, 629 
Melophia, 532 
Mentha, 178 
Merasmiese, 443, 445 

Key to, 445 

Merasmiopsis, 445 
Mercurialis, 344 
Merulieai, 416, 418 
Merulius Lacrymans, 418 
Mesospore, 327, 375, 384 
Mespilus, 570 
Metanectria, 198 
Metasphffiria, 252, 257 

Albescens, 257 

Michenera, 405 
Micothyriaceae, 170 
Microascus, 166 
Microcera, 207 
Micrococcus, 18, 21 

Albidus, 21 

Delacourianus, 21 

Flavidus, 21 

Imperatoris, 21 

■ Nuclei, 21 

Pellucidus, 21 

Phytophthorus, 21 

Populi, 21 

Tritici, 21 



Microdiplodia, 510 

Anthurii, 511 

Microglossum, 131 
Micropera, 518 
Microspatha, 634 
Microspha'ra, 175, 185 
Alni, 185, 186, 570 

Calocladophora, 106 

Extensa, 186 

Lonicera;, 186 

Vaccinii, 186 

Berberidis, 185 

Beta>, 187 

Diffusa, 186 

Elevata, 186 

Euphorbia;, 187 

Ferruginea, 187 

Grossularia?, 185, 185 

Microstroma, 396 

Album, 396 

Juglandis, 396 

Microthyriacea;, 170, 195 
Microthyrium Coffa;, 195 
Micro-type, 328 
Micula, 518 
Mignonette, 81, 631 
Mikronegeria, 336 
Millet, 90 
Milowia, 588 
Mitrula, 131, 132 

Sclcrotiorum, 132 

Mohonia, 379 

Molds, Slime. See Myxomycetes. 

Mollisia, 146 

Mollisiacese, 134, 146 

Key to, 146 

Mollisiella, 146 
Monacrosporium, 588 
Monascacea;, 118 
Monilia, 137, 138, 140, 567, 568 

Cinerea, 139, 569 

Crategi, 569 

Fimicola, 569 

Fructigena, 139, 569 

Laxa, 569 

Linhartiana, 569 



728 



INDEX 



Monilia, Seaveri, 140, 569 
Moniliaceaj Scolecosporsc, 592 
Moniliacese, 565 

Key to, 565 

Amerosporae, 565 

Key to, 565 

Chromosporiea^ 565 

Key to, 566 

Dictyosporaj, 565, 592 

Key to, 592 

— — - Didymospora;, 565, 585 

Key to, 585 

Helicospora;, 565, 593 

Oosoporeaj, 565, 567 

Key to, 567 

Phragmosporse, 565, 588 

Key to, 588 

Staurosporaj, 565, 593 

Key to, 593 

Moniliales, 464, 479, 554 

Key to, 465 

Monilochajtes, 596, 597 

Infuscans, 597 

Monoblepharidiales, 66 
Monochaetia, 558 

Pachyspora, 558 

Monocotyledones, 611 
Monographus, 217 
Monopodium, 576 
Monospore, 121 
Monosporium, 576 
Monotospora, 600 
Monotosporese, 595, 600 

Key to, 600 

Montagnella, 216 
Montagnites, 442 
Moon Flower, 82 
Morel, 114 

Morning Glory, 82, 337 
Mortierellacea;, 103 
Morus, 182, 202, 207, 231, 249, 
491, 499, 503, 512, 517, 525, 
562 
Mountain Ash, 39, 367, 368, 427 
Mucor, 90, 101, 104, 105, 106 
• Mucedo, 106 



Mucor, Pyriformis, 106 

Racemosus, 106 

Mucoraceae, 103, 107 

Key to, 104 

Mucorales, 66, 102 

Key to, 103 

Mucorese, 104 

Mucronella, 413 

Mucrosporium, 589 

Mulberry, 21, 31, 43, 52, 73, 393, 

445, 454, 499, 557, 561, 582, 626, 

658 
Mullerella, 236 
Munkia, 527 
Munkiella, 217 
Muricularia, 482, 527 
Muscari, 375 
Mushroom, 200, 398, 567, 569, 574, 

584, 587 
Muskmelon, 44, 51, 95, 247, 487 
Mutinus, 462 
Mycelia Sterilia, 479, 659 

Key to, 659 

Myceliophthora, 566, 567 

Lutea, 567 

Mycelophagus Castanese, 101 
Mycena, 450, 460, 461 

Epipterygia, 460 

Mycenastrum, 465 

Mycogala, 481 

Mycogone, 200, 586, 587, 587 

Perniciosa, 200, 587 

Rosea, 200, 587 

Mycoplasm Theory, 333 
Mycosphffirella, 236, 243, 484, 490, 

519, 525 

Abietis, 249 

Brassicsecola, 249, 484 

Cerasella, 245, 625 

■ Cinxia, 250 

CitruUina, 246, 2^8, 509 

CofTcEe, 249 

Coffeicola, 250 

Comedens, 249 

Convexula, 250 

Cydonise, 249 



INDEX 



729 



Mycosphserella, Elasticse, 249 

Fagi, 249 

Fragaria;, 244, 2^, 519, 590 

Fusca, 250 

Gibelliana, 249 

Gossypina, 248, 625 

Grossularise, 245 

Hedericola, 249 

Hondai, 250 

Laricina, 249, 530 

Loefgreni, 249 

Maculiformis, 249, 485, 562 

Mori, 557 

Morifolia, 249, 562 

Pinifolia, 249 

Pinodes, 250, 506 

Populi, 249, 519, 035 

Primulffi, 250 

Punctiformis, 249 

Rosigena, 249 

Rubina, 245 

Sentina, 246, 2Jt6, 247, 249, 519 

Shiraina, 250 

Stratiformans, 248 

Tabifica, 247, 485, 490 

Tamarindi, 250 

Taxi, 249 

Tulasnei, 247, 603 

Ulmi, 249, 484 

Vitis, 249 

MycosphserellacesE, 223, 235 

Key to, 235 

Mykosyrinx, 302 
Myrangiella, 170 

Orbicularis, 170 

Myrangium, 170 
Myriangiaceae, 165, 170 

Key to, 170 

Myriogenospora, 216 
Myriostoma, 465 
Myrmaiciella, 283 
Myrmfficiiim, 283 
Myroiphysa, 655 
Mystrosporium, 616, 620 

Abrodens, 620 

Aductxim, 620 



Mystrosporium, Alliorium, 620 
Myrothecium, 655 
Mytilidium, 164 
Myxobacteriales, 11 
Myxogastrales, 5, 9 

Key to, 9 

Myxomycetes, 1, 3, 5 

Key to, 5 

Myxormia, 538 
Myxosporella, 538 
Myxosporium, 274, 538, 546 

Abietinum, 547 

Carneum, 547 

Corticolum, 493, 5Jt6, 546 

Devastans, 647 

Lanceola, 547 

Longisporum, 547 

Mali, 547 

Piri, 547 

Valsoideum, 274, 646 

Myxotrichellese, 595 



N 



Naemosphsera, 501 
Najmospora, 122, 538, 647, 562 

Ampelicida, 238 

Coryli, 122 

Crocea, 547 

Napicladium, 609, 611 

Janseanum, 611 

Soraueri, 255, 611 

Narcissus, 389, 489, 523, 591, 592, 611 
Nasturtium, 37, 168, 260 
Naucoria, 449 
Necator, 640, 643 

Decretus, 643 

Necrosis, 281 

Nectarine, 604 

Nectria, 197, 201, 475, 646 

Amerunensis, 204 

Bainii, 204 

Bogoriensis, 205 

Bulbicola, 205 

Cinnabarina, 202, 202, 642 



730 



INDEX 



Nectria, Coffeicola, 204 

Cucurbitula, 203 

Ditissima, 203, 568 

Diversispora, 204 

— — Fruticola, 205 

Gigantispora, 205 

Goroshankianna, 205 

Graminicola, 205 

Ipomoeaj, 204, 20Jt, 205 

Jungeri, 205 

Luteopilosa, 205 

Pandani, 204 

Ribis, 204 

Rousselliana, 204, 656 

Solani, 204 

Striatospora, 205 

Theobromse, 205 

Theobromicola, 206 

— Vandse, 205 

Vanillse, 206 

Nectriaceae, 196 
Nectriese, 196 

Key to, 197 

Nectriella, 197 
Nectrioidacese, 479, 526 
Key to, 526 

Hyalodidymise, 526 

Hyalophragmiae, 526 

Hyalosporse, 526 

Key to, 526 

Ollulea;, 526 

— Phaeosporae, 526 

Scolecosporse, 526 

Zythieaj, 526 

Negeriella, 637 

Negundo, 260, 489 

Nematospora, 121 

Nematosporangium, 75 

Nemophila Auriculata, 168 

Neobarclaya, 556 

Neocosmospora, 197, 205, 475, 646, 

651 
Neolecta, 131 
Neomichelia, 609 
Neopeckia, 226 
Neottiospora, 482 



Neovossia, 314, 315 
Nephlyctis, 354 
Nicotinia, 101, 168, 178, 486 
Nidulariales, 396 
Niesslia, 225 
Nigrospora, 600 
Niptera, 147 
Nitschkia, 234 
Nolanea, 450 
Nothopatella, 501 
Nowakowskiella, 72 
Nummularia, 285 

Discreta, 285, 286 

Nyctaginacese, 303 



O 



Oak, 130, 152, 157, 162, 177, 186, 192, 
193, 203, 220, 231, 249, 264, 275, 
279, 281, 352, 396, 409, 410, 411, 
414, 415, 419, 421, 422, 424, 428, 
430, 434, 436, 439, 440, 442, 452, 
489, 498, 545, 546, 547, 555, 564, 
570, 603 

Oat, 23, 206, 213, 260, 301, 304, 305, 
306, 380, 383, 490, 520, 550, 607, 
608 

Oat Grass, 307 

Ochropsora, 336 

Sorbi, 336 

Odontia, 413 

Odontoglossum, 631 

CEdemansiella, 444 

(Edemium, 598 

(Edocephalum, 570 

ffinothera, 71 

Oidiopsis, 567 

Oidium, 60, 172, 567, 569 

Alphitoides, 570 

Ambrosia?, 178, 569 

Balsamii, 177, 669 

Chrysanthemi, 569 

Crsetsegi, 183, 569 

— — - Erysiphoides, 569 

Farinosum, 184, 569 



INDEX 



731 



Oidium, Fragariae, 175, 569 

Leucoconium, 170, 569 

Mespilinum, 570 

Monilioidcs, 179, 569 

Qucrcinum, 570 

Tabaci, 570 

Tuckeri, 181, 569 

Vcrbenae, 570 

Okra, 650, 651 

Olcacese, 164 

Oleander, 36, 45, 192, 193, 422, 524, 

631 
Oleina, 122 
Olive, 34, 45, 155, 192, 193, 433, 486, 

493, 543, 602, 624 
Olopecurus, 383 
Olpidiaceaj, 67, 69 

Key to, 68 

Olpidiopsis, 68 
Olpidium, 68, 69, 72 

Brassica;, 68, 69 

Olpitrichum, 575 

Ombrophileae, 136 

Omphalia, 450 

Oncidium, 356, 392, 544, 605 

Oncopodium, 615 

Oncospora, 537 

Onion, 41, 42, 43, 52, 97, 200, 377, 

491, 497, 499, 512, 520, 541, 549, 

574, 581, 604, 603, 616, 618, 

620 
Onobrychis, 168 
Onygenacese, 165 
Oochytriacea), 67, 75 

Key to, 73 

Oomyces, 199 
Oomycetes, 62, 65, 66, 101 
Oospora, 475, 567, 568, 568 

Abietum, 568 

Scabies, 568 

Ophiobolus, 252, 259, 259 

Graminis, 259 

Herpotrichus, 259 

Oryzeae, 259 

Ophioceras, 232 
Ophiochaeta, 252 



Ophiocladium, 566, 567 

Ilordii, 567, 567 

Ophiodothis, 216 
OphiomaK.saria, 262 
Ophionectria, 198, 207 

Coccicola, 207 

Foliicola, 207 

Ophiotrichum, 609 

Opsis-type, 328 

Opuntia, 544 

Orange, 207, 249, 256, 260, 409, 422, 

435, 445 
Orbicula, 189 
Orcadellaceae, 9 
Orchard Grass, 52, 550 
Orchid, 46, 52, 205, 270, 392, 500, 

541, 544, 547, 631 
Orchis, 344 

Ornithogalum, 71, 320 
Osage Orange, 346 
Ostreion, 164 
Ostropacese, 160 
Ostrya, 188 
Otthia, 234 
Ovularia, 243, 577, 582, 582 

Alnicola, 582 

Armoracia;, 582 

Canaigricola, 582 

Citri, 582 

Corcellensis, 582 

Exigua, 582 

Interstitialis, 582 

Medicaginis, 582 

Necans, 582 

Primulana, 582 

Rosea, 582 

Syringae, 582 

Vicise, 582 

Villiana, 582 

Ovulariopsis, 188, 577, 582 

Ulmorica, 582 

Oxalis, 168, 329, 384 
Ozier, 253 
Ozonium, 657, 661 
Omnivorum, 662 



732 



INDEX 



Pachybasium, 583 

Pachysterigma, 403 

Pactilia, 639 

Pajonia, 176, 178, 352 

Psepalopsis, 567 

Palm, 77, 88, 191, 323, 499, 545, 552, 

560, 658, 664 
Palmetto, 412 
Pandanus, 204, 531, 554 
Panicum, 305, 307, 310, 312, 314 
Pansy, 99, 320, 488, 552, 654 
Panus, 445, 446 

Stipicus, 446 

Papaver, 321, 322 

Papulospora, 570 

Paranectria, 198 

Para Rubber, 101, 415, 487, 512, 

614 
Paraspora, 588 
Parmularia, 163 
Parodiella, 189 
Parsley, 141, 377, 521 
Parsnip, 36, 41, 42, 91, 592, 628 
Paryphedria, 151 
Paspalum, 213 
Passalora, 602, 607 

Bacilligera, 607 

Microsperma, 607 

Patellariacese, 134 

Patellina, 639 

Patouillardia, 640 

Patzschkeella, 505 

Paulownia, 545 

Paxillea;, 442 

Pea, 28, 99, 177, 248, 250, 260, 329, 

373, 506, 519, 651 
Peach, 36, 53, 106, 128, 137, 138, 

176, 231, 268, 282, 357, 428, 485, 

490, 499, 512, 539, 540, 541, 547, 

560, 592, 604, 606 
Peanut, 392, 557, 629 
Pear, 38, 105, 130, 149, 202, 231, 246, 

249, 253, 255, 268, 367, 369, 371, 

404, 419, 421, 246. 279, 485, 490, 



502, 515, 519, 530, 540, 546, 547, 

553, 607 
Pearl Millet, 90 
Pecan, 250, 607, 632 
Pecia, 482 
Pedilospora, 593 
Pelargonium, 36, 43, 389, 544, 620, 

631 
Pellicularia, 382, 577, 582 

Koleroga, 583 

Pellioniella, 510 

Peltospha'ria, 276 

Peltostroma, 531 

Penicilliopsis, 167 

Penicillium, 166, 167, 169, 169, 572, 

573, 635 

Digitatum, 574 

Glaucum, 574 

Italicum, 574 

Luteum, 574 

Olivaceum, 574 

Peniophora, 406 

Pennisetum, 209 

Peony, 178, 529, 581, 606 

Pepper, 37, 42, 268, 269, 5^0, 541 

Peraphyllum, 371 

Peribotryum, 634 

Periconia, 598 

Periconiese, 594, 597 

Key to, 597 

Pcriconiella, 597 

Peridermium, 330, 333, 335, 336, 350, 

389, 390 

Acicolum, 337, 337 

Cerebrum, 352 

Cornui, 352 

Elatinum, 349 

Oblongisporium, 338 

Pyriforme, 352 

Rostrupi, 339 

— Strobi, 351 
Peridinese, 3 
Peridium, 325 
Periola, 641 
Perisporiacese, 170, 189 
Key to, 189 



INDEX 



733 



Perisporiales, IIG, 124, 165, 1G7, 

170 

Key to, 170 

Pcrisporium, 189 
Perithecium, 62, 63 
Peronoplasmopara, 83, 90, 93 

Celtidis, 93 

Cubensis, 93, 94 

Humuli, 93 

Peronospora, 78, 82, 84, 90, 93, 95, 

618 

Antirrhini, 101 

Arborescens, 100 

Candida, 101 

Cannabina, 101 

Conglomerata, 101 

Corolla}, 101 

Cytisi, 100 

Dianthi, 101 

Dipsaci, 100 

Effusa, 96, 96 

Ficaria;, 101 

Fragarise, 100 

Jaapiana, 101 

LifiarisB, 100 

Maydis, 101 

Myosotidis, 101 

Nicotianse, 101 

Parasitica, 95, 97 

Phoenixse, 101 

Potentillaj, 100 

Rubi, 100 

Schachtii, 100 

Schleideni, 96, 98 

Schleideniana, 96 

Sparsa, 97 

Trichomata, 100 

Trifoliorum, 97 

Valeriana;, 101 

Valerianella, 101 

Vicise, 97 

Vincae, 101 

Violacea, 100 

Violae, 99 

Peronosporacese, 78, 82 
Key to, 83 



Peronosporales, 66, 74, 75, 77, 
475 

Key to, 78 

Persimmon, 540, 581 
Pcstalozzia, 558 

Aloea, 560 

Clusise, 560 

Discosioides, 560 

Funerca, 559, S59 

Fuscescens, 560 

Sacchari, 560 

Gongrogena, 560 

Guepini, 559, 559 

Hartigii, 558 

Inquinans, 560 

Lupini, 560 

Palmarum, 560 

Palmicola, 560 

Pha^nicis, 560 

Richardiaj, 560 

Stictica, 560 

Suffocata, 560 

Tumefaciens, 560 

Uvicola, 559 

Pcstalozziella, 538 
Pestalozzina, 557 
Petunia, 48, 141 
Pezizaceae, 133, 134 
Pezizales, 123, 133 

Key to, 133 

Phacidiaceae, 154, 155 

Key to, 155 

Phacidiales, 124, 154 

Key to, 154 

Phacidiese, 156 
Phacidium, 156, 157 

Infestans, 157 

Phaconectria, 201 
Phseodon, 414 
Phajonectria, 201 
Phaeopeltosphaeria, 276 
Phseophyceae, 3 
Phseoseptoria, 517, 525 

Oryzae, 525 

Phaeosphseriella, 236 
Phallacese, 462 



734 



INDEX 



Phallales, 395, 462 

Key to, 462 

Phallus, 462, 463 

Impudicus, 463 

Rubicundus, 463 

Pharcidia, 236, 250 

Oryz£E, 250 

Phaseolus, 178, 187, 372 

Multiflorus, 168 

Vulgaris, 168 

Phellomyces, 614, 657 
Phlebia, 413 
Phlebophora, 406 

Phleospora, 243, 249, 518, 519, 
625 

Aceris, 525 

Caraganaj, 525 

Mori, 525 

Moricola, 525 

Oxycantha?, 525 

Phleum, 180, 321, 374, 608 

Phlox, 176, 178, 258, 497, 519, 523, 
631 

Phlycta?na, 493, 518 

Phoenix, 101, 658 

Pholiota, 449, 452 

Adiposa, 452, 453 

Aurivella, 452 

Cervinus, 452 

Destruens, 452 

Mutabilis, 452 

Spectabilis, 452 

Squarrosa, 452 

Phoma, 238, 243, 245, 247, 257, 279, 
325, 478, 481, 484, 490, 493, 519, 
532 

Albicans, 260, 490 

Aleracea, 491, 492 

Ambigua, 490 

Apiicola, 492 

Batata;, 492 

Betffi, 247, 490 

Bohemica, 276, 490 

Brassicse, 492 

Phoma, Chrysanthemi, 492 



Phoma, Citricarpa, 491 

Cyclamenae, 492 

Cydona;, 490 

DahUffi, 492 

Devastatrix, 492 

Hennebergii, 491 

Limonis, 490 

Lophiostomoides, 491 

Mah, 490 

Malvacearum, 492 

Mororum, 491 

Myxiae, 491 

Napobrassica;, 491 

Oleandrina, 492 

Oleracea, 491, 492 

Persicse, 490 

Pithya, 492 

Pomarum, 491 

Ileniformis, 242, 490 

Ribesia, 492 

Roumii, 492 

Sanguinolenta, 491 

■ Sarmentella, 490 

Solani, 491 

Solanicola, 491 

Sordida, 492 

Sphserosperma, 247 

Strobi, 492 

Strobilinum, 492 

Subcircinata, 491 

Tiliaj, 259 

Tuberculata, 491 

Uvicola, 238 

Phomatospora, 263 
Phomopsis, 482, 493 

Aloeapercrassse, 493 

Stewartii, 493 

Phorcys, 263 
Phragmidium, 354, 358, 390 

Americanum, 359, 359 

Bulbosum, 358 

Disciflorum, 359, 359 

Montivagum, 359, 359 

Rosaj-acicularis, 359 

RosEe-arkansana;, 359, 359 

Rosse-caUfornicse, 359, 359 



INDEX 



735 



Phragmidium, Rosae-setigerae, 359, 

359 

Rubi-idaei, 359 

Speciosum, 359 

Subcorticium, 359 

Violacoum, 359 

Phragmites, 315, 377, 378 
Phragmopyxis, 354 
Phragraosporse, 633, G37 

Key to, 637 

Phycomyces, 105 

Phycomycetes, 1, 3, 59, 64, 65, 101, 

113, 116, 118 

Key to, 65 

Phyllachora, 157, 217, 220, 221, 606, 

607 

Cynodontis, 221 

Dapazioides, 221 

Graminis, 220, 220 

Makrospora, 221 

Poffi, 221 

Pomigena, 220 

Sorghi, 221 

Trifolii, 220, 606 

Ulmi, 557 

Phyllactinia, 171, 173, 175, 187, 

582 

Corylea, 174, 187, 188 

Phyllostachys, 215 

Phyllosticta, 148, 238, 242, 243, 325, 

476, 481, 483, 490, 519 

Acericola, 489 

Aceris, 489 

Altha?ina, 487 

Ampelopsidis, 484 

— Apii, 487 

Argillacea, 487 

Armenicola, 486 

— — - Bataticola, 486 

Bellunensis, 249, 484 

Beta;, 486 

Bizzozeriana, 486 

Brassicse, 484 

Brassica?cola, 249 

Cannabinis, 486 

Catalpae, 489 



Phyllosticta, Cavara;, 489 

Chenopodii, 487 

Chrysanthcrni, 488 

Cinnanioni, 487 

Circum.scissa, 486 

Citrullina, 487 

Coffeicola, 486 

Comoensis, 486 

Cruenta, 488 

Cucurbitacearum, 487, 629 

Cyclaminis, 488 

Dammara;, 489 

Dianthi, 488 

Digitalis, 488 

Dracffinae, 489 

Fragaricola, 486 

Funckia, 489 

Grossularia;, 486 

Halstedii, 488 

Hederacea, 487 

Hedericola, 487 

Hevea, 487 

Hortorum, 487 

Humuli, 486 

Hydrangea?, 488 

Ida?cola, 488 

Ilicina, 489 

Insulata, 486 

Japonica, 486 

Labrusca;, 238, 484 

Leucanthemi, 488 

Liliicola, 488 

Limitata, 485 

Maculicola, 487 

Maculiformis, 2^9, 485 

Magnolia;, 489 

Malkcffi, 486 

Medicaginis, 486 

Minima, 489 

Miuria, 486 

Narcissi, 489 

Nicotiana, 486 

Nobilis, 489 

Olea;, 486 

Opuntia;, 488 

Paviae, 489 



736 



INDEX 



Phyllosticta, Persicse, 486 

Phaseolina, 487 

Piricola, 485 

Pirina, 485 

Primulicola, 488 

Prunicola, 486 

Pteridis, 489 

Putrefaciens, 486 

Richardiae, 488 

Rosae, 487 

Rosarum, 487 

Solitaria, 484, 485, 485 

Sphaeropsidea, 489 

Succedanea, 486 

Syringae, 488 

Tabaci, 486 

Tabifica, 247, 485 

Tilia;, 489 

Ulmicola, 489 

Vialae, 486 

■ Vincse-minoris, 488 

Viola}, 488 

Viridis, 489 

Vitis, 486 

Phymatotrichum, 576 
Physalacria, 412 
Physalis, 48, 322 
Physalospora, 238, 251, 252, i 
539 

Abietina, 253 

Cattleyae, 253, 541 

Fallaciosa, 253 

: Gregaria, 252, 494 

Laburni, 253 

Vanilte, 253 

Woronini, 253 

Physaraceae, 10, 11 

Key to, 11 

Physarella, 12 
Physarum, 12, 12 

Bivalve, 12 

— - Cinereum, 12 
Physoderma, 72 
Physopella, 340, 345 

Fici, 345 

Vitis, 345 



?, 273, 



Physospora, 575 

Phytolacca, 408 

Phytomyxa Leguminosarum, 8 

Phytophthora, 78, 83, 84, 88, 90, 617 

Agaves, 89 

Cactorum, 88 

Calocasise, 89 

Faberi, 88 

Fagi, 88 

Infestans, 84, 85, 86, 87 

Nicotianae, 89 

Omnivora, 88, 89 

Arecae, 88 

Phaseoli, 84, 84, 86 

Sempervivi, 88 

Syringae, 88 

Picea, 145, 235, 253, 349, 391, 408 
Pichia, 121 
Piggotia, 528, 530 

Astroidea, 221, 530 

Fraxini, 530 

Pigweed, 408 
Pilacre, 634 
Pilaira, 104 
Pileotaria, 354 
Piloboleae, 104 
Pilobolus, 104 

Crystallinus, 105 

Pilocratera, 135 
Pilosace, 449 
Pinaceae, 88 

Pine, 22, 52, 141, 145, 151, 157, 161, 
162, 203, 230, 233, 249, 330, 333, 

351, 352, 391, 401, 415, 418, 419, 
423, 424, 432, 431, 436, 438, 440, 
446, 454, 460, 492, 499, 512, 515, 
516, 524, 531, 532, 654, 660 

Pineapple, 496, 512, 596 

Pink, 349, 507 

Pinus, 161, 337, 338, 339, 340, 351, 

352, 390, 408 
Pionnotes, 645 

Betae, 645 

Rhizophila, 645 

Piptocephalidacese, 103 
Piptostomum, 481 



INDEX 



737 



Pirella, 105 
Piricularia, 589, 591 

Caudata, 592 

Grisea, 591, 591, 614 

Oryzff, 592, G14 

Pirobasidium, 033 
Pirostoma, 531 

Farnctianum, 531 

Pirotta;a, 147 
Pistillaria, 412 
Pisum, 168, 178, 372, 605 
Pithomyces, 645 
Pitya, 136 
PlacosphaM'ia, 483 
Placospharella, 505 
Plagiorhabdus, 483, 500 

Oxycocci, 500, 500 

Planococcus, 18 
Planosarcina, 18 
Plantago, 69, 96, 179 
Plasmodiophora, 6 

Brassica;, 6, 7 

. Californica, 8 

Humili, 8 

Orchidis, 8 

. Tomati, 8 

_— Vitis, 8 
Plasmodiophorales, 5 

— — Key to, 6 

Plasmopara, 82, 83, 90, 93, 95 

■ Halstedii, 91 

. Nivea, 91 

. Obducens, 93 

Pygmsea, 93 

Ribicola, 92 

Viticola, 91, 92 

Platanus, 186, 205, 535 

Platygloiea, 392 

Plectothrix, 576 

Plenodomus, 482 

Pleococcum, 534 

Pleogibberella, 198 

Pleolpidium, 68 

Pleomassaria, 263 

Pleomeliola, 190 

Hyphsenes, 193 



Pleonectria, 198, 207 

Berolinensis, 207 

Coffcicola, 207 

Pleophragmia, 224 
Pleosphserulina, 236, 250 

Briosiana, 250 

Pleospora, 252,259,^.79,611,618 

Albicans, 260, 269, 490 

Avense, 262 

Bromi, 261, 613 

Gramineum, 261, 612 

Herbarum, 260, 618 

. Hesperidearum, 260, 616 

Hyacinthi, 260, 603 

Infectoria, 260 

Negundinis, 260 

Oryza;, 260 

Pisi, 260 

Putrefaciens, 260 

Teres, 262 

Trichostoma, 260, 262, 612, 621 

Tritici, 258 

- Tritici-repentis, 262, 613 

. Tropoeoli, 260, 621 

Ulmi, 260 

Vulgaris, 610 

Pleosporaceje, 223, 250 

Key to, 251 

Plcotrachelus, 68 
Pleurotus, 450, 454, 569 

- Atrocoeruleus, 455 

Corticatus, 455 

. Mitis, 455 

Nidulans, 455 

Ostreatus, 454, J^56 

Salignus, 454 

Ulmarius, 454 

Plowrightia, 216, 217 

Agav.es, 220 

Morbosa, 218, 218, 219, 516 

. Ribesia, 220 

Virgultorum, 220 

Plum, 32, 38, 129, 138, 184, 219, 271, 
278, 282, 357, 433, 516, 520, 562, 
586, 604 
Pockets, 129 



738 



INDEX 



Pluteolus, 449 
Pluteus, 450, 454 

Cervinus, 454, 1^55 

Poa, 8, 119, 180, 221, 310, 321, 375 

Pocillum, 136 

Pocosphaeria, 252 

Podocapsa, 122 

Podocarpus, 597 

Podocrea, 199 

Podosphsera, 175, 182 

Leucotricha, 184, 569 

Myrtillina, 183 

Oxyacantha;, 183, 183, ISA, 569 

Tridactyla, 183, 184 

Podosporiella, 637 
Podosporium, 637 
Polemonium, 507 
Polycephalum, 633 
Polyscytalum, 568 
Polydesmus, 609 
Polygonum, 96, 303 
Polymorphism, 64 
Polynema, 534 
Polyphagus, 73 
Polyporacese, 402, 416 

Key to, 416 

PolyporeEe, 416 
Polyporus, 417, 418, 426 

Adustus, 426 

Amarus, 422 

Betulinus, 425, 425 

Borealis, m, 423, 4^3 

Dryadeus, 423 

Dryophillus, 421 

Fruticum, 422 

Giganteus, 421 

Glivus, 421 

Hispidus, 421 

— — Obtusus, 418 

Schweinitzii, 400, 401, 424 

Squamosus, 419, J,20 

Sulphureus, 419, 419 

Polystictus, 417, 418, 426 

Cinnabarinus, 425 

— — Hirsutus, 426 
Occidentalis, 425 



Polystictus, Pergamenus, 426, 4^6 

Sanguineus, 425 

Velutinus, 425 

Versicolor, 425, 427 

Polystigma, 198, 207 

Ochraceum, 208 

Rubra, 208, 208, 564 

Polythelis, 354 
Polythrincium, 602, 606 

Trifolii, 220, 606, 606 

Pomelo, 549, 604 

Pomes, 139, 237, 255, 278, 282, 362, 

410, 491, 496, 502, 529, 569, 607, 

649 
Poplar, 21, 36, 47, 130, 182, 256, 340, 

342, 419, 433, 440, 446, 454, 507, 

535, 556, 606 
Poppy, 100 

Mallow, 390 

Populus, 127, 130, 249, 344, 499, 512, 

519, 545, 555 
Poria, 418 

Hypolaterita, 418 

Laevigata, 418 

Subacida, 418 

Vaporaria, 418 

Vineta, 418 

PoropeUis, 531 

Porothelium, 440 

Potato, 8, 21, 40, 41, 43, 44, 46, 47, 

48, 49, 69, 70, 86, 141, 200, 231, 

258, 404, 408, 456, 491, 497, 568, 

583, 584, 591, 614, 616, 617, 623, 

624, 627, 637, 645, 652, 653 

Beetle, 48 

Potentilla, 175 
Powdery Mildew, 171 
Primrose, 101, 250, 320, 552, 582 
Primula, 315, 318, 488, 507, 579, 582, 

591 
Primulaceae, 101 
Prismaria, 593 
Privet, 191, 269, 541 
Promycelium, 63, 300 
Prophytroma, 600 
Prospodium, 354 



INDEX 



739 



Prosthemiella, 557 
Prosthemium, 515 
Protoascomycetes, 114, 117, 119 
Protobasidii, 299, 323 

Key to, 323 

Protocoronospora, 405, 409 

Nigricans, 409 

Protodiscales, 114, 123, 125 

Key to, 125 

Protomyces, 118, 119 

Macrosporus, 119 

Pachydermus, 119 

Rhizobius, 119 

Protomycetacea?, 118 

Key to, 118 

Protomycetales, 118 

Key to, 118 

Protostegia, 536 

Prunus, 129, 130, 140, 152, 182, 183, 

184, 202, 208, 275, 347, 357, 486, 

495, 496, 563, 564, 569, 579, 605, 

610, 626 
Psathyra, 449 
Pseudobeltrania, 602 
Pseudocenangium, 537 
Pseudocolus, 463 
Pseudodematophora, 231 
Pseudographis, 156 
Pseudographium, 515 
Pseudomassaria, 262 
Pseudomeliola, 189 
Pseudomonas, 18, 21, 22 

.^ruginosus, 23, 27 

Amaranti, 22 

Aralise, 39 

Avens, 23, 23, 40 

Campestris, 22, 24, 24, 25, 26, 

28, 29, 31, 32, 43 

Destructans, 26, 39, 42 

Dianthi, 22, 27 

Fluorescens, 27, 41 

Exitiosus, 27 

Liquefaciens, 27 

Putrida, 27 

Hyacinthi, 22, 25, 27, 28, 31 

■ Indigofera, 13 



Pseudomonas, Iridis, 27 

Juglandis, 27 

Legurninipordus, 28 

Levistici, 28 

Maculicolum, 28 

Malvacearum, 22, 29, 29 

Medicaginis, 29, 30, 31 

Michiganense, 30 

Mori, 30, 43 

Oleae-tuberculosis, 34 

Phaseoli, 22, 27, 28, 31, 31 

Pruni, 32, 32 

Putridus, 23 

Putrifaciens Liquefaciens, 43 

Iladicicola, 8, 32 

Savastanoi, 33, 46 

Sesami, 34 

Sps. Indet, 37 

Stewarti, 22, 33, 34, 34 

Syringae, 35 

Tumefaciens, 35, 35 

Vascularum, 37 

Pseudopatella, 536 
Pseudopeziza, 147, 149, 475, 539, 
547, 555 

Medicaginis, 147 

Ribis, 148, 541 

Salicis, 148, 541 

Tracheiphila, 148 

Trifolii, 148, 148, 494, 535 

Pscudophacidea?, 155 
Pseudophacidium, 155 
Pseudoplasmopara, 93 
Pseudorhytisma, 156 
Pseudotryblidium, 150 
Pseudotsuga, 408, 416 
Pseudovalsa, 280, 281 

Longipes, 281 

Pseudozythia, 527 
Psilocary, 303 
Psilocybe, 449, 451 

Henningsii, 451 

Pennata, 4'52 

Spadicea, 451 

Psilopezia, 132 
Psilospora, 534 



740 



INDEX 



Pteris, 489, 595 

Pterocarpus Indicus, 426 

Pterophyllus, 444 

Pterula, 411 

Puccinia, 355, 359, 361, 375, 390 

AUii, 377 

Anemones-virginianse, 389 

Apii, 377 

Arenarise, 387 

Asparagi, 326, 328, 329, 330, 

376, 376 

Asteris, 389 

BuUata, 377 

Canna;, 389 

Castagnei, 377 

Cerasi, 376 

Chrysanthemi, 386 

Cichorii, 378 

Convallarise-digraphidis, 388 

Coronata, 382, 383 

Coronifera, 383 

Cyani, 377 

Dianthi, 389 

Dispersa, 382 

Endiviaj, 377 

Fagopyri, 378 

Gentianaj, 389 

Gladioli, 389 

Glumarum, 383 

Graminis, 329, 334, 378, 379, 

385 

Airse, 379 

Avense, 379 

Phlei-pratensis, 379 

Poaj, 379 

Secalis, 379 

Tritici, 379 

Granulans, 389 

Helianthi, 386, 387 

Heterogena, 386 

Horiana, 389 

Iridis, 389 

IsiaciB, 378, 390 

Magnusii, 376 

Malvacearum, 328, 385, 386 

Menthai, 378 



Puccinia, Pazschkei, 389 

Persistens, 389 

Phlei-pratensis, 384 

Phragmitis, 377 

Poarum, 386 

PodophyUi, 332 

Porri, 377 

Pringsheimiana, 376 

Purpurea, 384 

Ribis, 328 

caricis, 376 

Nigri-acuta?, 376 

paniculatse, 376 

Pseudocyperi, 376 

Rubigovera, 329, 381, 383 

Secalis, 382 

Tritici, 382 

Schroeteri, 389 

Scilla;, 389 

Simplex, 383 

Sorghi, 329, 384, 384 

Suaveolens, 328 

Taraxici, 378 

Tragopogonis, 328, 377 

Triticina, 382 

Tulips, 389 

Vexans, 327 

Viote, 388 

Pucciniacese, 335, 353 

Key to, 353 

Pucciniastrum, 341, 346, 390, 391 

Abieti-chamsenerii, 347 

Epilobii, 347 

Goeppertianum, 342, 347 

Hydrangeae, 346 

Myrtelli, 347 

Padi, 347 

Pustulatum, 347 

Pucciniosita, 342 
Pucciniospora, 505 
Puff-balls, 395 
Pulparia, 151 
Pulsatilla, 333 

Pumpkin, 95, 107, 247, 408, 548 
Purslane, 82, 408 
Pycnidium, 61 



INDEX 



741 



Pycnochytrium, 70, 72 
— — Anemones, 72 
— — Globosum, 72 
Pyrenochaeta, 482, 497 

Ferox, 497 

Oryzse, 497 

Phlogis, 497 

Pyrenomycetes, 159, 165, 170, 195, 

217 
Pyrenopeziza, 147 
Pyrenophora, 252, 262 

Trichostoma, 262 

Pyrenotrichum, 481 
Pyroctonum, 72 

Sphairicum, 73 

Pyronema, 116 
Pyronemaccae, 133, 134 
Pyropolyporous Praerimosa, 430 
Pyrus, 176, 183, 366, 590 

Arbutifolia, 369 

Pythiacea;, 75 
Pythiacystis, 75, 77, Tl 

Citrophthora, 77 

Pythium, 75, 76, 76, 650 

de Baryanum, 77 

Gracile, 77 

Intermedium, 77 

Palmivorum, 77 



Q 



Quercus. 127, 186, 188, 202, 220, 544 
Quince, 36, 38, 130, 140, 149, 249, 
267, 268, 367, 369, 371, 404, 490, 
502, 515, 540, 542, 557, 569, 582 



R 

Rabenhorstia, 483 

Rabentischia, 251 

Radish, 36, 42, 81, 95, 408, 571 

Radulum, 413 

Ramularia, 243, 245, 589, 590 

Armoracise, 590, 590 



Ramularia, Betae, 690 

Coleosporii, 591 

Cynarae, 591 

Geranii, 591 

Goeldiana, 591 

Heraclci, 591 

Lactea, 591 

Modesta, 591 

Narcissi, 591 

Necator, 590 

Onobrychidis, 591 

Primula?, 591 

Spinaciae, 690 

Taraxaci, 590 

Tulasnei, 244, 690 

Vallambrosae, 591 

Ramulaspera, 577 

Ranunculacese, 93, 320 

Ranunculus, 101, 321, 375 

Rape, 141, 258 

Raspberry, 38, 245, 248, 257, 258, 

270, 359, 360, 451, 503, 543, 544, 

547, 581, 650 
Ravenelia, 353 
Red Algse, 3 
Red Bud, 632 
Red Cedar, 329, 431 
Redtop, 310 
Reessia, 68 
Rehmiella, 264 276 
Rehmiellopsis, 264, 276, 490 

Bohemica, 276 

Reticulariacese, 10 
Rhabdospora, 518, 519, 625 

Coffea;, 519, 525 

Coffeicola, 519, 525 

Oxycocci, 519, 525 

Rubi, 519, 525 

Theobromae, 519, 525 

Rhacodium, 657 
Rhacophyllus, 444 
Rhagadolobium, 155 
Rhamphoria, 232 
Rhamus, 383 
Rhinocladium, 599 
Rhinotrichum, 575 



742 



INDEX 



Rhizidiacese, 67 
Rhizina, 132 

Inflata, 132, 133 

Undulata, 132 

Rhizinacese, 131, 132 

Key to, 132 

Rhizoctonia, 230, 231, 407, 408, 657, 

659 

Betse, 660 

Crocorum, 660 

Medicaginis, 660 

Solani, 407, 660 

Strobi, 660 

Subepigea, 660 

Violacea, 407, 6G0 

Rhizogaster, 462 
Rhizomorpha, 659 
Rhizopus, 104, 105, 105 

Necans, 106 

Nigricans, 105 

Schizans, 106 

Riiododendron, 141, 194, 221, 258, 

349, 398, 544, 559 
Rhodophycea?, 3 
Rhombostilbella, 634, 635 

Rosa?, 635 

Rhopalidium, 557 
Rhopographus, 217 
Rhopalomyces, 570 
Rhubarb, 41, 101, 377, 497, 506 
Rhynchodiplodia, 510 

Citri, 510 

Rhynchomeliola, 232 
Rhynchomyces, 609 
Rhynchophoma, 505 
Rhynchosporium, 586, 587 

Graminicola, 587 

Rhynchostoma, 232, 277 
Rhytidhysterium, 161 
Rhytidopeziza, 150 
Rhytisma, 156, 158 

Acerinum, 158, 159, 530 

Punctatum, 159, 530 

Salicinum, 159, 530 

Symmetricum, 159 

Ribes, 152, 176, 185, 188, 202, 220, 



328, 344, 351, 376, 486, 541, 

580, 581 
Riccia, 251 
Rice, 46, 213, 214, 232, 250, 257, 

259, 260, 276, 317, 486, 495, 

503, 504, 507, 512, 516, 520, 

535, 591, 605, 611, 613, 626, 

656, 661 
Richardia, 408 
Richonia, 189 
Riccoa, 637 
Rimbachia, 443 
Robillarda, 505 
Robinia, 235, 524 
Roesleria Hypogsea, 154 
Roostelia, 335, 361, 363, 389, 391 

Aurantica, 368 

Botryapites, 370 

Cancellata, 369 

Cornuta, 368 

Cydoniaj, 371 

Koreaensis, 371 

Penicillata, 367 

Pyrata, 364, S91 

Transformans, 369 

Rosa, 33, 47, 97, 105, 176, 220, 

284, 359, 433, 487, 492, 503, 

505, 509, 516, 517, 522, 544, 

560, 564, 602, 631 
Rosacea, 127, 143, 330, 359, 

610 
Rosellc, 187 
Rosellinia, 226, 230, 635 

Aquila, 230, 231 

Bothrina, 231 

Echinata, 232 

Ligniaria, 232 

Massinkii, 231 

Necatrix, 230, 231 

Quercina, 231 

Radiciperda, 231 

Rosenscheldia, 216 
Rostrella, 166 

Coffcffi, 168 

Rotaea, 588 
Rozites, 449 



542, 



258, 
497, 
525, 
643, 



249, 
504, 
555, 

391, 



INDEX 



743 



Roumegueriella, 527 

Roussoella, 216 

Rozella, 70 

Rubber plant, 270 

Rubus, 39, 72, 100, 176, 227, 333, 359, 
361, 626 

Rumex, 74, 377, 582 

Ruppia, 8 

Rush, 329 

Rust Fungi, 64, 298, 324 

Rutabaga, 27 

Rutstroemia, 135 

Rye, 146, 180, 200, 206, 213, 257, 
258, 262, 305, 310, 317, 319, 333, 
380, 382, 520, 550, 555, 587, 613 

Rynchospora, 303 



Sabina, 234 
Saccardsea, 630 
Saccardia, 190 
Saccardoella, 252 
Saccharomycetacea', 120 

Key to, 121 

Saccharomyccs, 121 

Croci, 121 

Saccharomycetales, 119 

Key to, 120 

Saccharomycodes, 121 

Saccharomycopsis, 121 

Saccharum, 180 

Saccoblastia, 393 

Saffron, 660 

Sagittaria, 315 

Sainfoin, 217, 507, 591, 595 

Salix, 148, 256, 344, 494, 541, 606 

Salsify, 36, 42, 52, 82, 301, 328, 

617 
Sambucus, 185, 220, 256 
Sanguisorba, 361 
Santiella, 515 
Sapindacese, 127 
Saponaria, 620 
Saprolegniaceae, 75 



Saprolegniales, 66, 74, 75 

Key to, 75 

Sarcapodiese, 595 
Sarcina, 18 

Sarcinella, 191, 61(), 625 
Sarcinodochium, 645 
Sarcomyces, 151 
Sarcoscypha, 135 
Sarcoscypheaj, 135 
Sarcosoma, 151 
Sarracenia, 270 
Sassafras, 433 
Satsuma, 604 
Saxifrage, 345, 389 
Scabiosa, 100, 176, 178 
Scaphidium, 536 
Sceptromyces, 584 
Schenckiella, 189 
Schinzia, 323 
Schizanthus, 552 
Schizomycetes, 1, 3, 13, 18 

Key to, 18 

Schizonella, 302 
Schizophyllese, 443, 444 

Key to, 444 

Schizophyllum, 444 

Alneum, 444, 44-5 

Schizosaccharomyces, 121 
Schizothyrella, 536 
Schizothyrium, 156 
Schweinitzia, 150 
Schweinitziella, 217 
Scilla, 143, 375, 389 
Scirrhia, 217 
Scirrhiella, 217 
Sclerodermatales, 398 
Scleroderris, 155 
Sclerodiscus, 655 
Sclcrophoma, 482 
Sclerospora, 82, 83, 89 

Graminicola, 90, 90, 101 

Macrospora, 89 

Sclerotinia, 135, 136, 138, 568 

Alni, 143 

Aucuparia;, 143 

Betulaj, 143 



744 



INDEX 



Sclerotinia, Bulborum, 143 

Cinerea, 137, 139, 569 

Crata?gi, 143, 569 

Fructigena, 137, 139, 569 

Fuckeliana, 139, 140, 141, 579, 

581 

Galanthi, 141, 581 

Laxa, 137, 139, 569 

Ledi, 137, 329 

Libertiana, 140, 141, 141, 11^2, 

581 

Linhartiana, 140, 569 

Mespili, 140 

Nicotiana;, 142 

Oxycocci, 140, 569 

Padi, 140, 569 

Rhododendri, 141 

Seaveri, 140, 569 

Trifoliorum, 143 

Tuberosa, 143 

Urnula, 1S7 

Sclerotiopsis, 482 
Sclerotium, 659, 660 

Bulborum, 661 

Cepivorum, 661 

Oryzffi, 661 

Rhizodes, 661 

Rolfsii, 660, 661, 662 

Tulipse, 661 

Tuliparum, 143, 661 

Scolecopeltis Jiruginea, 195 
Scolecosporium, 557 
Scolecotrichum, 602, 607 

Avenae, 608 

Fraxini, 608 

Graminis, 608, 608 

Iridis, 608 

Melophthorum, 608 

Musse, 608 

Scorias, 190 
Scoriomyces, 641 
Scorzonera, 305 
Secale, 180, 379 
Sedge, 89, 220, 329 
Sedum, 221, 497, 522 
Seiridiella, 558 



Seiridium, 558 

Selenotila, 566 

Selinia, 198 

Sempervivum, 353 

Senecio, 168, 333, 339 

Sepedonium, 200, 577 

Septobasidium, 405, 411 

Pedicellata, 412 

Septocylindrium, 588, 589 

Areola, 589, 589 

Radicicolum, 590 

Rufomaculans, 589 

Septodothideopsis, 518 

Septogloeum, 243, 556, 557 

Arachidis, 557 

Cydonise, 557 

Fraxini, 557 

Hartigianum, 557 

Manihotis, 557 

Mori, 249, 557 

Profusum, 557 

Ulmi, 557 

Septomyxa, 555 

Septonema, 609 

Septorella, 517 

Septoria, 243, 257, 265, 478, 517, 518 

Aciculosa, 519 

^sculi, 524 

Ampelina, 520 

Antirrhini, 522 

Armoracise, 522 

Avena?, 520 

Azalese, 523 

Beta;, 520 

Canabina, 521 

Caragana;, 524 

Castanese, 524 

Castanicola, 524 

Cerasina, 520 

Cercidis, 524 

Chrysanthemella, 522 

Citrulli, 520 

Consimilis, 522 

Cornicola, 524 

Cucurbit acearum, 521 

Curvata, 524 



INDEX 



745 



Septoria, Curvula, 520 

Cyclaminis, 522 

Dianthi, 522 

Divaricata, 523 

Dolichi, 521 

Exotica, 523 

Fairmanii, 523 

Fragaria;, 519 

Fraxani, 524 

Glaucescens, 520 

Glumarum, 520 

Graminum, 520 

Hedera;, 522 

Helianthi, 523 

Hippocastani, 524 

Hydrangese, 622 

Iridis, 522 

Lactucae, 522 

Limonum, 520 

Locfgreni, 520 

Longispora, 520 

Lycopersici, 521, 5122 

Majalis, 523 

Medicaginis, 621 

Narcissi, 523 

Nicotians?, 521 

Nigro-maculans, 524 

Nodorum, 520 

Ochroleuca, 524 

Oleandrina, 524 

Parasitica, 523, 524 

Petroselini, 521 

Apii, 621, 521 

Phlogis, 258, 519 

Pini, 162 

Piricola, 246, 519 

Pisi, 250, 519 

Populi, 249, 619 

Pruni, 620 

Pseudoplatani, 524 

Ribis, 245, 519, 519 

Rosa;, 522 

Rostrupii, 522 

Secalina, 520 

Sedi, 522 

Spadicea, 524 



Septoria, Tilise, 524 

Tritici, 520 

Ulmaria;, 524 

Ulmi, 221 

Varians, 522 

Veronica;, 624 

Septosporiella, 518 
Septosporium, 616, 620 

Heterosporium, 620 

Sequoia, 243, 632 

Service Berry, 191 

Sesame, 34, 47 

Setaria, 90, 209, 213, 305 

Shad Bush, 39 

Sida, 488 

Sigmoideomyces, 570 

SilHa, 283 

Simblum, 464 

Sircoccus, 482 

Sirodesmium, 615 

Siropatella, 536 

Sirothecium, 500 

Sirozythia, 526 

Sisil, 552 

Sistotrema, 413 

Skepperia, 406 

Slime Flux, 120 

Slime Fungi, 3 

Slime Molds, 1 

Smut Fungi, 298 

Smuts, 64 

Snapdragon, 101, 492, 522, 553 

Snowdrops, 141, 581 

Sobralia, 270 

Soft Rot, 105 

Solanaceous, 86 

Solanum, 322, 323, 408 

Solenia, 406 

Sohdago, 179, 338 

Solomon's Seal, 488 

Sorbus, 235, 255, 336, 368, 371, 607 

Sordaria, 224 

Sordariacese, 222, 224 

Key to, 224 

Sorghum, 49, 121, 221, 305, 310, 311, 
312, 314, 384, 613 



746 



INDEX 



Sorokina, 151 
Sorolpidium, 8 

Betae, 8 

Sorosphsera, 6, 8 

Graminis, 8 

Sorosporium, 302, 312, 812 

Consanguineum, 312 

Dianthi, 312 

Ellisii, 312 

Everhartii, 312 

Sorothelia, 227 
Sparassis, 412 
Spathularia, 131 
Speira, 615 
Spelt, 206 
Spermatia, 325 
Spermodermia, 655 
Spermogonia, 324, 325 
Sphacelia, 196, 211, 212, 640, 643 

Segetum, 213, 643 

Typhina, 643 

Sphacelotheca, 302, 303, 310 

Reiliana, 312, 312 

Sorghi, 311, 311 

Sphaerella, 244 
Sphaeriaceffi, 222, 225 

Key to, 225 

Sphseriales, 124, 195, 221, 475 

Key to, 222 

Sphscridium, 641 
Spha?rioidacese, 479, 480 
— Key to, 480 

Amerosporae, 480 

Dictyospora?, 480 

Didymospora?, 480 

Helicospora>, 480 

Hyalodictya?, 480 

Hyalodidymff, 480, 505 

Key to, 505 

Hyalophragmia?, 480, 513 

Key to, 513 

Hyalosporae, 480 

Key to, 480 

Phffiodictyaj, 480, 516 

Key to, 516 

Pha^odidymse, 480, 509 



Sphserioidacea?, Phseodidymse, Key 

to, 510 

Phffiophragmise, 480, 514 

Key to, 514 

Phaeospora;, 480, 500 

Key to, 500 

Phragmosporse, 480 

Scolecosporae, 480, 517 

Key to, 517 

Staurosporse, 480 

Sphajrita, 68, 238 
Sphffirocolla, 640 
Spha;rographium, 517 
Sphajromyces, 656 
Sphseronema, 482, 494 

Adiposum, 495 

Fimbriatum, 494, ^95 

Oryzse, 495 

— — Phacidioides, 148, 494 

Pomarum, 495 

Spurium, 152, 495 

Sphaironemella, 527 
Spha;ropeziza, 156 
Sphajrophragmium, 454 
Sphaeropsdidales, 479, 564 

Key to, 479 

Sphaeropsis, 284, 501 

Japonicum, 503 

Magnolia?, 503 

Malorum, 284, 502, 502, 546 

Mori, 503 

Pseudodiplodia, 503 

Ulmi, 503 

Vincae, 503 

Viticola, 284 

SphsDrosoma, 132 
Sphaerosporium, 639 
Sphajrostilbe, 195, 196, 198, 207 

Flavida, 207 

Repens, 207 

Sphajrotheca, 172, 175 

Castagnci, 115 

— Humuli, 175, 569 

Var. Fuliginea, 176 

Lancstris, 177 

Mali, 184 



mDEX 



747 



Sphirrotheca, Mors-uvse, 176, 176 

Pannosa, 176, 5G9 

Sphajrulina, 236 
Sphinetrina, 153 
Spicaria, 201, 584, 585 

Colorans, 205, 585 

Solani, 585 

Spicularia, 571 

Spilomium, 655 

Spinach, 90, 321, 487, 551, 590, 605, 

611, 628, 629 
Spinellus, 104 
Spirea, 175, 176, 184, 336, 524, 

637 
Spirechnia, 354 
Spirillacese, 19 
Spirilli, 13 
Spirillum, Cholerse-asiatica;, 19 

Volutans, 13 

Spirodelia, 315 
Spondylocladium, 609, 614 

Atrovirens, 614, 614 

Spongospora, 6, 8 

Subterranea, 8 

Sporidium, 326 
Sporocybe, 630 
Sporoderma, 640 
Sporodesmium, 257, 615, 61S, 617 

Brassicse, 617 

Dolichopus, 617 

Exitiosum, 258, 616 

Var. Solani, 616 

Glomerulosum, 610 

Ignobile, 617 

Melongense, 617 

Mucosum, 617 

Piriforme, 260, 616 

Putrefaciens, 617 

Scorzonerse, 617 

— — Solani Varians, 617 
Sporoglena, COO 
Sporonema, 274, 534, 535 

Oxycocci, 535, 535 

Phacidioides, 148, 535 

Platani, 274, 535 

Pulvinatum, 536 



iSporormia, 224 
Sporormiella, 224 
Sporoschismea), 609 
Sporotrichella, 576 
Sporotrichuni, 230, 576, 577 

Poa', 577, 578 

Spruce, 145, 162, 230, 391, 418, 423, 

424, 431, 432, 434, 436, 438, 440, 

509, 524 
Spumaria, 11 

Alba, 11 

Spumariacea;, 10, 11 

Spurge, 544 

Squash, 95, 105, 179, 247, 540, 548 

Stachybotryella, 598 

Stachybotrys, 598 

Stachylidieaj, 595 

Stagonospora, 514, 514 

Carpathica, 514 

Iridis, 514 

Staurochseta, 482 
Staurosporse, 633 
Steccherinum, 414, 416 

Ballouii, 416 

Stemmaria, 630 
Stemonitaceae, 10 
Stemphyliopsis, 592 
Stemphylium, 616, 617, 617 

Citri, 618 

Ericoctonum, 617 

Tritici, 618 

Stenocybe, 153 
Stereum, 405, 409 

Frustulosum, 409, 410 

Hirsutum, 409 

Purpureum, 410 

Quercinum, 409 

Rugosum, 410 

Sterigma, 298 

Sterigmatocystis, 167, 310, 572, 573 

Ficuum, 573 

Luteo-nigra, 573 

Niger, 573 

Stictidaceffi, 154 
Stictis, 154, 155 
Panizzei, 155 



748 



INDEX 



Stigmatea, 150, 236, 243, 2^3, 244 

Alni, 243 

Juniperi, 243 

Stigmatella, 641 
Stigmella, 615 
Stigmina, 608, 610, 610 

Briosiana, 610 

Stilbacese, 565, 632 

Key to, 632 

Amerosporse, 632 

Key to, 633 

Didymosporse, 632 

Helicospora?, 632 

Hyalostilbea^, 632, 633 

Phaiostilbese, 632 

Phragmospora}, 632 

Stilbella, 633, 635 

Flavida, 635 

— Nanum, 635 

Populi, 635 

Thea;, 635 

Stilbonectria, 198 

Stilbospora, 558 

Stilbothamnium, 630 

Stilbum, 207 

Stone Fruits, 139, 278, 569 

Stoneworts, 3 

Strawberry, 11, 52, 100, 176, 486, 

494, 507, 519, 529, 542, 555, 590, 

591 
Streptococcus, 18 
Streptothrix, 599 

Dassonvillei, 599 

Stromatinia, 137 
Stropharia, 448 
Strumella, 655, 656 

Sacchari, 666 

Stuartella, 226 
Stypinella, 393 

Mompa, 393 

Stypinellese, 392 
Stysanus, 630, 636, 638 

Stemonites, 637 

Ulmaria}, 637 

Veronicae, 637 

Sugar-beet, 22, 36, 37, 41, 408 



Sugar Cane, 37, 47, 206, 209, 227, 228, 
248, 258, 305, 374, 392, 448, 463, 
464, 495. 499, 503, 512, 554, 560, 
596, 606, 620, 630, 656 

Maple, 415 

Sulla, 277, 630 

Sunflower, 179, 321, 523 

Swamp Cedar, 416 

Sweet Pea, 37, 268 

Pepper, 37 

Potato, 82, 105, 204, 337, 408, 

■ 486, 492, 495, 513, 574, 597, 606, 
663 

William, 508 

Sycamore, 275, 498, 524, 525, 541, 
546, 560, 580, 603 

Sydowia, 236 

Symphoricarpus, 187 

Symphytum, 178 

Synchytriacea;, 67, 69 

Key to, 70 

Synchytrium, 70, 70 

Endobioticum, 70 

Papillatum, 71 

Vaccini, 71, 71 

Sj^nsporium, 598 

Synthetospora, 593 

Syringa, 35, 186 

Syzygites, 104 



Tamarind, 250, 546 
Tapesia, 146 
Taphrina, 126 

Aurea, 127 

Bassei, 130 

Bullata, 130 

Coerulescens, 127 

Communis, 130 

Cratajgi, 130 

Decipiens, 130 

Deformans, 127, 128, 129 

Farlowii, 130 

Insititia), 130 



INDEX 



749 



Taphrina, Johonsonii, 127 

Longipes, 129 

Maculans, 130 

Mirabilis, 129 

Pruni, 128 

Rhizipes, 129 

Rostrupiana, 130 

Theobromae, 130 

Ulmi, 127 

Taphrinopsis, 126 

Taraxacum, 176 

Taxus, 192, 259, 493 

Tea, 8, 231, 243, 263, 287, 403, 409, 

411, 415, 418, 438, 448, 544, 553, 

614, 630, 635 
Teasel, 100 
Tecoma, 631 
Teleutospore, 326, 327 
Telia, 326 

Terfeziacese, 165, 166 
Testicularia, 303 
Testudina, 167 
Tetracium, 593 
Tetracladium, 593 
Tetracoccosporium, 616 
Tetradia Salicicola, 252 
Tetramyxa, 6, 8 
Tetraploa, 615 
Thalictrum, 321, 389 
Thallophyta, 2 
Thamnidieae, 105 
Thaxteria, 227 
Thecaphora, 302, 313, SIS 

Deformans, 313 

Thecospora, 641 
Thelephora, 406, 410 

Galactina, 411 

Laciniata, 4iO, 411 

Thelephoracese, 402, 405, 433 

Key to, 405 

Theleporus, 440 
Thelocarpon, 197 
Theobroma, 205 
Therrya, 251 
Thielavia, 166, 167 
Basicola, 167, 168 



Thielaviopsis, 595, 596 

Ethaceticus, 228, 696 

Paradoxa, 590 

Podocarpi, 597 

Thiobacteriales, 19 

Thistle, 328 

Thoracella, 505 

Thozetia, 641 

Thyridella, 278 

Thyridium, 278 

Thyrococcum, 658 

Sirakoffi, 658 

Thyronectria, 198 

Thyrsidium, 553 

Tiarospora, 505 

Tichothecium, 236 

Tilachlidium, 633 

Tilia, 193, 202, 489, 509, 524, 545, 
631, 658 

Tilletia, 301, 314, 315 

FcEtens, 315, 316 

Glomerulata, 315 

Hordei, 317 

Horrida, 317 

Panicii, 315 

Secalis, 317 

Texana, 316 

Tritici, 316, 317 

Tilletiaceae, 302, 314 

Key to, 314 

Tilmadoche, 12 

Timber, 415 

Timothy, 24, 310, 385, 550 

Titania, 280 

Tites, 593, 593 

Maxilliformis, 593 

Toad Stool, 398 

Tobacco, 27, 33, 44, 45, 48, 50, 52, 69, 
89, 143, 260, 486, 506, 521, 570, 
573, 581, 619, 621, 624, 627, 654 

Tolypomyria, 576 

Tolyposporella, 303 

Tolyposporium, 302, 313, S14 

BuUatum, 313 

Filiferum, 314 

Volkensii, 314 



750 



INDEX 



Tomato, 21, 27, 30, 36, 41, 42, 44, 47, 
52, 86, 268, 497, 522, 540, 551, 564, 
605, 608, 623, 624, 643, 653 

Tomentella, 403 

Torsellia, 483 

Torula, 191, 595, 596, 597 

Exitiosa, 597 

Sphasrclla, 597 

Torulea;, 594, 595 

Key to, 595 

Toxins, 2 

Toxosporium, 557, 568 

Abietinum, 558 

Trabutia, 276 

Trachyspora, 354 

Tracya, 315 

Tracyella, 528 

Tragopogon, 178, 310, 378 

Trametes, 417, 437 

Pini, 401, 437 

Radiciperda, 401, 431 

Robinophila, 438 

Suaveolens, 438 

Thea;, 438 

Tranzschelia, 354, 356 

Punctata, 356, 357 

Trees, 193, 407, 409, 411, 426, 428, 
432, 451, 452, 453, 454, 460, 568, 
662 

Coniferous, 418, 419, 424, 433, 

440, 456 

Deciduous, 414, 418, 419, 421, 

425, 427, 430, 452, 454, 456 

Forest, 132, 153 

Fruit, 418, 421, 439 

Nut, 420, 439 

Orchard, 419 

Ornamental, 421 

Shade, 419 

Timber, 419, 448 

Treleasiella, 527 

Tremellales, 323 

Trichsegum, 616 

Trichiacese, 9 

Trichobelonium, 146 

Trichobotrys, 598 



Trichocladium, 602 
Trichocollonema, 517 
Trichocomacea', 165 
Trichoderma, 571 
Trichodytes, 562 
Tricholoma, 123, 450, 460, 460 

Rutilans, 460 

Saponaceum, 460 

Trichopeltulum, 528 
Trichopezizese, 135 
Trichophila, 529 
Trichopsora, 336 
Trichoseptoria, 517, 518 

Alpei, 518 

Trichosphseria, 226, 228, 228, 554, 
596 

Sacchari, 228 

Trichosporiea}, 594, 598 

'Key to, 598 

Trichosporium, 599 
Trichostroma, 655 
Trichotheca, 639 
Trichothecium, 586 
Trichurus, 630 
Tridentaria, 593 
Trientalis, 315 

TrifoHum, 168, 178, 313, 373, 374 
Trigonella Coerulea, 168 
Trimmotostroma, 657, C57 

Abietina, 657 

Trinacrium, 593 
Triphragmium, 354, 358 

Ulmariaj, 358, 358 

Triplicaria, 655 

Triticum, 180, 260, 262, 379 

Trochila, 156, 157, 158, 539 

Craterium, 157, 541 

Popularum, 157, 555 

Trogia, 443, 444 

Faginea, 443 

Tropajolum, 37, 81, 362, 621 
Trullula, 553, 554 

Vanillae, 554 

Tryblidiaceae, 151, 154 
Tryblidiella, 150 
Tsuga, 229, 391, 416 



INDEX 



751 



Tubaria, 449 

Tuberales, 124 

Tubercularia, 196, 201, 396, 639, 642, 
642 

Fici, 6Jt2, 642 

Vulgaris, 202, 642 

Tuberculariaceffi, 565, 638 

Key to, 638 

Dematiese, 638 

Key to, 655 

Amerosporse, 638, 654 

Dictyospora;, 639, 658 

DidymosporEe, 638 

Helicospora?, 639 

Phragmosporip, 639, 657 

Key to, 657 

Scolecosporie, 639 

Staurospora), 639 

Mucedinese, 638 

Amerosporese, 638, 639 

Key to, 639, 

Dictyosporse, 638 

Didymosporse, 638 

Helicosporaj, 638 

Phragmosporse, 638, 645 

Key to, 645 

Staurosporae, 638 

Tuberculina, 335, 640, 643 

Tuburcinia, 315 

Tulip, 143, 310, 389, 564, 661 

Tumeric, 130 

Tupelo, 412 

Turnip, 25, 26, 36, 41, 42, 44, 46, 81, 
95, 177, 568, 592, 619 

Tympanis, 151 

Typha, 188 

Typhula, 412 

Graminum, 412 

Variabilis, 412, US 



U 



Uleomyces, 199 
Ulmaria, 358 
Ulmus, 188, 202, 610 



Umbellifers, 6, 74, 91, 377, 592, 

607 
Uncigera, 583 
Uncinula, 175, 180 

Aceris, 182 

Circinata, 182 

Clandestina, 182 

Flexuosa, 182 

Mori, 182 

Necator, 181, 181 182, 569 

Prunastri, 182 

Salicis, 182 

Uredinales, 137, 323, 394, 475, 643 

Key to, 335 

Biologic Specialization, 332 

Cytology, 330 

Form Genera, 334 

Imperfecti, 335 

Key to, 389 

Infection Experiments, 334 

Uredinium, 325 

Uredinopsis, 341, 391 

Uredo, 334, 335, 389, 390, 392 

Arachidis, 392 

Aurantiaca, 392 

Autumnalis, 392 

Kuhnii, 392 

Muelleri, 361 

Orchidis, 392 

Satyrii, 392 

Tropajoli, 392 

Uredospore, 327 
Urobasidium, 403 
Urocystis, 301, 314, 318 

Agropyri, 320 

Anemonis, 320 

Cepula?, 318, 318, 319 

Colchici, 320 • 

Gladioli, 320 

Italica, 320 

Kmetiana, 320 

Occulta, 319, 319 

Ornithogali, 320 

Primulicola, 320 

Violffi, 319 

Urohendersonia, 515 



752 



INDEX 



Uromyces, 355, 371, 375, 390 

Appendiculatus, 371, S72, 373 

Betse, 374, 374 

Caryophyllinus, 328, 375 

Colchici, 375 

Dactylidis, 374 

Ervi, 375 

Erythronii, 375 

Fabse, 373 

Fallens, 374 

Ficariaj, 375 

Jaffrini, 375 

Kuhnei, 374 

Medicaginis, 374 

Minor, 374 

Pallidus, 375 

— Pisi, 329, 330, 372, 374 
Pose, 375 

Scillarum, 375 

— Trifolii, 373, 373, 374 
Uromycladium, 327 
Urophlyctis, 73 

— Alfalfa?, 74 

Hemispherica, 74 

Kriegeriana, 74 

Leproides, 73 

Major, 74 

Pluriannulata, 74 

Pulposa, 74, 74 

Rubsaameri, 74 

Trifolii, 74 

Uropyxis, 354 
Urospora, 251 
Urosporium, 608 
Ustilaginacese, 301, 302 

Key to, 302 

Ustilaginales, 214, 299, 326, 392 

Key to, 302 

Ustilaginoidea, 199, 213, 214, 640, 643 

Virens, 214, 214, 643 

Ustilaginoidella, 199, 214, 650 

Graminicola, 214 

Musaeperda, 214 

(Edipigera, 214 

Ustilago, 299, 300, 301 302, 303, 310, 
311, 312, 313, 315 



Ustilago, Avena;, 303, 303, 306 

Bulgarica, 305 

Crameri, 304 

Cruenta, 310 

Crus-galli, 305 

Esculenta, 310 

Ficuum, 310 

Fischeri, 310 

Hordei, 305, 306 

La;vis, 306, 306 

Macrospora, 306 

Medians, 305 

Nuda, 306, 308 

Panici Miliacei, 310 

Perennans, 307 

Phoenicus, 310 

Rabenhorstiana, 307 

Sacchari, 305 

Scorzonorse, 305 

Secalis, 310 

Shiriana, 310 

Sphajrogena, 310 

Striajformis, 309 

Tragopogonis, 310 

Pratensis, 305 

Tritici, 307, 307 

Tulipae, 310 

— Vaillantii, 310 

Violacea, 310 

Vrieseana, 310 

Zese, 308, 308, 309 

Ustulina, 285, 286 
Zonata, 287 



Vaccinium, 184, 234, 242, 347, 397, 

543, 569 
Valerian, 101 
Valeriana, 178 
Valerian ella, 101 
Valsa, 208, 277, 278 

Ambiens, 278 

Caulivora, 278 

(Eutypa) Erumpens, 278 



INDEX 



753 



Valsa (Eutypolla) Prunastri, 278 

Leucostoma, 278 

Oxystoma, 278 

ValsaceiE, 223, 277 

Key to, 277 

Valsaria, 279 

Valsonectria, 198, 208, 208, 484 

Parasitica, 208 

Vanda, 205, 544 
Vanguicria, 356 
Vanilla, 204, 205, 253, 280, 375, 510, 

553, 554, 607 
Vegetables, 51, 105 
Velutaria, 150 
Venturia, 251, 253, 227 

— Cerasi, 255, 606 

Chlorospora, 606 

Crata?gi, 255 

Ditricha, 255, 607 

Fraxini, 255, 606 

Insequalis, 253, 354, 607, 611 

Cinerascens, 255, 607 

Pomi, 253 

Pyrina, 253, 607 

Tremula^, 255, 607 

Verbena, 176, 178, 187, 570 
Vermicularia, 482, 496, 564 

Circinans, 497 

Concentrica, 497 

Dematium, 496, 496 

Dcnudata, 497 

Melicffi, 497 

Microchffita, 497 

Polygoni-virginica, 497 

Subeffigurata, 497 

Telephii, 497 

— Trichella, 496 

Varians, 497 

Veronica, 8, 69, 523, 524, 637 
Verticillieffl, 566, 583 

Key to, 583 

Verticilliopsis, 583, 584 

Infestans, 584 

Verticillium, 196, 200, 583, 684, 587 

■ Albo-atrum, 584 

Vetch, 99, 373, 409, 506 



Viala-a, 277 

Vibernum, 404 

Vibrio Rugula, 15 

Vicia, 99, 178, 313, 372, 375, 408, 

508, 582 
Vigna Sinensis, 168 
Vinca, 101, 488, 503 
Violet, 72, 73, 96, 99, 168, 176, 320, 

388, 416, 488, 507, 544, 556, 591, 

599, 620, 630 
Virgaria, 599 

Vitis, 181, 238, 323, 620, 624 
Volutella, 497, 564, 641, 644 

Buxi, 204 

Concentrica, 645 

Dianthi, 645 

Fructi, 644, 644 

Leucotricha, 644 

Volutellaria, 641 
Volutina, 641 
Volvaria, 449, 452 
Bombycina, 453, 4^4 



W 



Walnut, 28, 275, 419, 421, 428, 430, 
524, 555, 606 

Water Lilies, 322 

Oak, 435 

Watermelon, 247, 408, 490, 521, 540, 
598, 629, 651 

Weinmannodora, 501 

Wheat, 21, 73, 90, 180, 200, 205, 206, 
207, 213, 257, 258, 304, 307, 308, 
316, 329, 333, 349, 379, 380, 382, 
412, 491, 493, 520, 550, 571, 572, 
587, 600, 613, 618 

Willia, 121 

Willow, 36, 44, 155, 157, 158, 159, 
182, 284, 340, 342, 344, 421, 428, 
433, 438, 454, 509, 530, 560, 582 

Wisteria, 21 

Witches Broom, 126, 130, 191, 211, 
215, 330, 348, 349, 369, 648 

Wojnowicia, 515 



754 



INDEX 



Woronina, 70 
Woroniniella, 70 
Wound Parasites, 399 



Yeasts, 120, 121 
Yew, 249 
Ypsilonia, 482 
Yucca, 503 



Z 



Xanthoxylum, 188 
Xenodochus, 355, 361 

Carbonarium, 361 

Xenopus, 575 
Xenosporium, 615 
Xerotus, 445 
Xylariaceae, 224, 284 

Key to, 285 

XylarieiE, 285 
Xylocladium, 637 
Xylostroma, 657, 663 
Xylotroma, 659, 633 



Yam, 543 
Yeast, 301 



Zea, 384 
Zignoclla, 227 
Zingiber, 46, 52, 130 
Zinnia, 141 
Zizania, 310 
Zopfia, 189 
Zopfiella, 189 
Zukalia, 190, 191 

Stuhlmanniana, 191 

Zygochytriacea?, 67 
Zygodesmus, 599 

Albidus, 599 

Zygomycetes, 66, 101, 114 

Key to, 102 

Zygorhynchus, 104 
Zygosaccharomyces, 121 
Zythia, 527 
Fragaria;, 527 



T 



HE following pages contain advertisements of books 
by the same author or on kindred subjects. 



Diseases of Economic Plants 



By F. L. STEVENS, Ph.D. 
Professor of Botany and V(>gctable Pathology of the North Carolina 
College of Agriculture and Mechanic Arts and Biologist of the Agri-'.'. 
cultural Experiment Station • • = 

AND 

J. G. HALL, M.A. 

Assistant in Vegetable Pathology in the North Carolina Agricultural 

Experiment Station 

Cloth, illustrated, 12mo, 523 -pp., $2.00 net; hy mail, $2.19 

Students of Plant Diseases are naturally divided into two categories. 
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such a way that reliable diagnoses may be made, and fully discusses the 
best methods of prevention or cure for these diseases. 

In this volume only such characters are used as appear to the naked 
eye or through the aid of a hand lens, and all technical discussion is 
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or exhibits peculiarities, knowledge of which may be of use in prophylaxis. 

While, in the main, non-parasitic diseases are not discussed, a few of 
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diseases caused by the most common parasitic flowering plants. 

A brief statement regarding the nature of bacteria and fungi and the 
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Nearly 200 excellent illustrations greatly increase the practical value of 
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CONTENTS 

Preface — Introductory — Historical — Damage Caused by Plant Dis- 
eases — Symptoms of Disease — Prevention or Cure of Plant Diseases — 
Public Plant Sanitation — Fungicides — Spraying Machinery — Cost of 
Spraying — Profits from Spraying — Soil Disinfection — General Diseases — 
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Smuts, General; Cereal Rusts, General; Anthracnose of Cereals; Special 
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eral Diseases, Special Hosts; Ornamental Plants — Appendix — Index. 



PUBLISHED BY 

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Publishers 64-66 Fifth Avenue New YorJe 



Diseases of Cultivated Plants and Trees 

By GEORGE MASSEE 

Assistant Keeper, Herbarium, Royal Botanic Gardens, Kew. Author of 

"British Fungus Flora," "Text-Book of Plant Diseases," "Plant 

World" and "Text-book of Fungi" 

Cluth, illustrated, 8vo, xii-\-602 pp., indexes, $2.25 net; by mail, $2.44 

A practical work, embodying the results of the researches of 
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not only represents accurately the views of others but gives rea- 
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This volume takes the place of the author's " Text-book of Plant 
Diseases," the issue of which has become exhausted, but follows 
somewhat different lines, and covers a much wider field. In addi- 
tion to a discussion of the causes and cure of the various fungi and 
parasitic diseases, there are chapters on Wounds (caused by prun- 
ing, wind, snow, etc.); Drought; Injuries due to Frost and Hail; 
Injury by Smoke, Acid, Fumes, Gas, etc.; Injuries caused by 
Animals and Birds; The Bacteriology of the Soil; and other val- 
uable topics. 

The treatment though technical, is sufficiently concise and clear 
to be easily comprehended by the least scientific. 

BY THE SAME AUTHOR 

A Text-Book of Fungi 

Illustrated, 8vo, $2.00 net 

This book supplies not only botanical information as to the various 
fungi which attack useful and ornamental plants, but gives the gardener 
and orchardist a manual for the cure and prevention of these pests. The 
author is a specialist of wide reputation and one of the assistants at the 
Kew Botanical Gardens. 



PUBLISHED BY 

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Plant Physiology 



By 



B. M. DUGGAR 
Professor of Plant Physiology in Cornell University 

Cloth, 12mo, $1.60 net 

FROM THE PREFACE 

" The engineer who does not understand his machine cannot expect 
to get effective work out of it. He should know its intimate structure, 
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and cold; the relation to the disease environment. 



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NOW READY FOURTH ENGLISH EDITION 8 VO. $5.00 NET 

A Text-Book of Botany 

By Dr. EDWARD STRASBURGER Dr. LUDWIG JOST 

Professor in the University of Bonn Professor in the University of 

Strasburg 

Dr. HEINRICH SCHENCK Dr. GEORGE KARSTEN 

Professor in the Technical Academy of Professor in the University of 

Darmstadt Halle 

Fourth English Edition, Revised with the Tenth German Edition 

By W. H. LANG, M.B., D.Sc, F.R.S. 
Barker Professor of Cryptogamic Botany in the University of Manchester 

With 782 illustrations, in part coloured 

PREFATORY NOTE 

The first edition of the English translation of this text-book was the work of 
Dr. H. C. Porter, Assistant Instructor of Botany, University of Pennsylvania. 
The proofs of this edition were revised by Professor Seward, M.A., F.R.S. The 
second English edition was based upon Dr. Porter's translation, which was revised 
with the fifth German edition. The present edition has been similarly revised 
throughout with the tenth German edition. Such extensive changes, including the 
substitution of completely new sections on Physiology and Phanerogamia, have 
however been made in the work since it was first translated, and in the third and 
fourth English editions, that it seems advisable to give in outline the history of the 
English translation instead of retaining Dr. Porter's name on the title-page. 

The ofhcial plants mentioned under the Natural Orders are those of the British 
Pharmacopceia instead of those official in Germany, Switzerland, and Austria, 
which are given in the original. ... 

PRESS NOTICES OF FORMER EDITIONS 

"The translator has been most successful in his work, the book reading as though 
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tant." — Nature. 

"The whole style of the book is admirable; the type, illustrations, and general 
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Knowledge. 

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"This work includes the most essential knowledge of several special books, it is 
almost a library in itself, and is moreover, a guide to botanical literature. It is well 
worth its price, and should be looked upon as a necessary possession." — Garden. 



PUBLISHED BY 

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Household Bacteriology 



By 

ESTELLE D. BUCHANAN, M.S. 
Recently Assistant Professor of Botany, Iowa State College 



ROBERT EARLE BUCHANAN, Ph.D. 

Professor of Bacteriology, Iowa State College, and Bacteriologist of the 

Iowa Agricultural Experiment Station 

Cloth, 8uo, xv-\-53G pp., index, $2.25 net 

The word Household is used as an extension rather than a limitation of 
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volume is, therefore, a general textbook of micro-biology in which special 
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molds, and makes possible the satisfactory identification of all forms or- 
dinarily encountered by the student. The work embodies the results of 
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— Boston Advertiser. 



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NOV 6 1913 



-mm 



